FE: EVAP large leak detected!!! Again???

[mcw323is]

Alright so this is getting ridiculous. This is literally the 4th time I have pulled this code from table 11, FE: evap large leak detected. Everytime I have asked about this people say oh its probably just your gas cap. I did a search and could not find anything. Is it really just my gas cap or should I be worried about something else? I don't want to drive around making a problem worse. I believe that evap refers to the fuel evaporatory system but I do not exactly know what other parts might be at fault.

A little info on things I have noticed if this helps any of you experts out there. The light seems to come on shortly after filling up a fresh tank of gas (roughly 25-30 miles into the tank). Also the last 2 times it has come on I distinctly remember sitting at the same light which is slightly down hill and is a notoriously long light. I doubt that means anything but at any rate i really would love some help or insight of any sort. Thanks!
-Matt

[amancuso]

Not to be a stickler, but have you *tried* replacing the gas cap?

[Mistermotorist]

I don't know about what investigation you have done already, but if you leave the ignition on while fueling, you will get the code which, will stay on for about 20-30 on-off ignition key initiation cycles - happened to me...I was listening to my mighty HK while fillin' the tank...

[mcw323is]

Not to be a stickler, but have you *tried* replacing the gas cap?

I haven't tried replacing the cap yet. I suppose I could try that first.


I don't know about what investigation you have done already, but if you leave the ignition on while fueling, you will get the code which, will stay on for about 20-30 on-off ignition key initiation cycles - happened to me...I was listening to my mighty HK while fillin' the tank...

Well not much investigation has been done but I never leave the keys in the ignition while fueling.

[HGS]

I have been repeatedly getting the OBDII code for small evap leak that according to the dealer is traceable to a bad fuel cap. A new fuel cap from the dealer was $11.00 so I tried it and cleared the code with my scanner. After a day the CEL came back on with the same code. So much for the new fuel cap solution.

In your case if it were the fuel cap I think it would come up with the code for a small or minor leak not a major one.

Does anyone know what sensor picks these errors up and where it is located ?

[HoboPro]

i just failed the smog test in CA, i didnt have a check engine light on so i take the car into the shop and he pulled the code saying that there was a evap leak code found prior and that the check engine light was probably reset and looks like the gas cap was replaced. he says that the computer needs to now "relearn" and reset itself. his suggestion was to drive around for about 150miles and it should do the trick. im to take it back to him in a few days and hope that it works...otherwise i can pass the smog and get the car registered. any other ideas if this doesnt work????

[vml]

In January's Roundel Brett Anderson replied to a tech question like yours and explained that the most common fault was filling the tank with the ignition on or having a loose cap but if you are having consistent faults you probably have a "fracture fitting under the spare tire in the tank". I don't know were exactly this fitting would be.

[HoboPro]

yea, it seems after doing a "evap leak" search that this is a very common problem. the tech told me that the check engine light was previously reset and it seems that the gas cap was replaced already. the thing is that up to this point since i bought the car( about 4 days), the check engine light hasnt lit up yet.

[HoboPro]

ok, just did a search on this and it's amazing how many people have this issue but no one seems to have the solution. i understand that most of the time it's the gas cap and you can reset the engine light but the code is still stored in the computer. So what have you guys done when it came down to getting to pass the emissions test? do we have to just hope that the computer resets itself? or am i looking at taking this down to the dealership and dropping some obscene $$$?

[Bimmer Pilot]

Check your charcoal canister under the spare tire (black plastic housing). That would seem to be the source of your recurring code. Its purpose is to absorb gasoline fumes.

The gas cap would solve a small evap leak...

[HoboPro]

ok, thanks, that's good to know. the thing is that im not getting any check engine light. i only found this out when i tried to pass the emission test here in Cali. so im not sure if i need to fix anything at this point. does the comp need to reset itself so that the code that is stored is "erased" in order for me to pass?

ive also read that another culprit may be a broken nipple on the recovery tank. The newer one would have a brass liner that goes deeper into the base of the nipple. anyone have any illustrations for this?

again, it appears that the previous owner has already been down this route.

[HoboPro]

update: so i tried to retest HOPING that it'll pass smog after driving about 100miles and HOPING that the code will disappear. Didnt happen...luckily this testing station offers free retest for failed test. so i zip over to the dealer and explained my situation. the reply i get from the tech was that most of these stations dont know how to test BMW's. "you have to run the engine hard until it gets really hot for sometime. keep the rpms up and bring it in immediately, not letting the car cool off and then test. it'll pass then, it happens all the time" (btw, smog test at the dealer is $145 + $140 labor). so to me that didnt sound right but decide to give it a shot..run the 101 for about 15mins, bring it back and the smog tech was kind enough to run a readiness test, car not ready to test yet. the tech turns to me and says that dealership is full of it. so now he tells me to pull my car out of the test stall, he pulls his car in (99VW Golf), runs smog on his car, takes my paperwork and proceeds to PASS mine using his car! Shhhh....i went for a walk and wasnt there to witness it. off to the DMV, all registered now..hmmm?

something to revisit in a couple of yrs??!?

[jdowpe]

WOW, this is a common problem!! See my post under EVAP & jdowpe.
'97 528 with 93,000 miles
My code is a little different "FA-EVAP TEV not operating" and the light goes on and off or I can reset it. Anyway, I tried the gas cap...no help either.
Apparently no one really knows.
If anyonehas info let me know. I have Bimmer maintenance disks and they don't have info either. Seems to be a common issue that there is no data on.

Thanks,
jim@dowworld.us

[dmurray14]

update: so i tried to retest HOPING that it'll pass smog after driving about 100miles and HOPING that the code will disappear. Didnt happen...luckily this testing station offers free retest for failed test. so i zip over to the dealer and explained my situation. the reply i get from the tech was that most of these stations dont know how to test BMW's. "you have to run the engine hard until it gets really hot for sometime. keep the rpms up and bring it in immediately, not letting the car cool off and then test. it'll pass then, it happens all the time" (btw, smog test at the dealer is $145 + $140 labor). so to me that didnt sound right but decide to give it a shot..run the 101 for about 15mins, bring it back and the smog tech was kind enough to run a readiness test, car not ready to test yet. the tech turns to me and says that dealership is full of it. so now he tells me to pull my car out of the test stall, he pulls his car in (99VW Golf), runs smog on his car, takes my paperwork and proceeds to PASS mine using his car! Shhhh....i went for a walk and wasnt there to witness it. off to the DMV, all registered now..hmmm?

something to revisit in a couple of yrs??!?

Wow, I think you get an award for managing to find the one inspection guy who isn't a jerk.

[jay00f4]

ive also read that another culprit may be a broken nipple on the recovery tank. The newer one would have a brass liner that goes deeper into the base of the nipple. anyone have any illustrations for this?

again, it appears that the previous owner has already been down this route.[/QUOTE]

This was the cause of my $400 bill. Took them forever to find the problem. Mine had the newer upgraded one already done. So it took them a long time to find it.

[jdowpe]

This is the orginal poster. It was a fuel purge valve located on the front of the engine driver's side. It has several hoses to it. $78 for the part. Been fine since then.
Thnaks,
JIM :)

[vml]

How did you find out?

[Tiptronik]

Were there no shops in the area that could do a leak test with a smoke machine to find the leak? Any decently equipped shop should have a flat rate to diagnose EVAP leaks (it doesn't have to be BMW), especially for air care.

[jdowpe]

There is another Forum out there @ http://bimmer.roadfly.com/bmw/forums/e39/

It is not as good as this one nor as user friendly. I just tried it searching the same things I do here and found it.

If you have a 528, there is an excellent tip section with lots of fixes and alterations. go to: http://www.bmwtips.com/

[PerfectLine328]

ive had this problem on my 96 328is...i drove around with the CE light on for about a year and a half because i could never figure it out. Both dealer and the auto shop i go to said it was the fuel cap and replaced it several times, only to have the light come back on. Evntually i gave up and didnt really care.

Then came time for my smog check, and i couldnt pass the test untill that light was turned off. I took it back to my shop and told them i NEED the problem fixed. Took them 4 days excluding sunday to check and repair a lot of the other problems i was having with my car and for them to figure out that there was a leak in my evap hose?? They fixed, test drove 20 miles, fixed test drove another 20 miles, and over again (110 miles worth of test driving) untill they figured out/pin pointed what the problem was. Apparently theres 10? or so of these hoses and few of them were damaged. They were replacedl; i got the car back today so tomorrow ill check if the CE light stays off .
TOTAL: $1,200
(inclduing my AC unit which was a goner and got that replaced/reprogrammed)

im gonna be really pissed/upset if my CE light comes back on

[jdowpe]

I think the difference here is that my error was "EVAP TEV not operating". That's the purge valve. I had to determine that the valve was bad. It had electrical. there wasn't anything else left. I had no "leak" error.

[PerfectLine328]

ARRGHHHHHHHHHH MY CE LIGHT CAME BACK ON....now i really give up

[dmurray14]

OK, if you give up, I'll give you my address...feel free to ship the car to me ;)

[Unicron]

A little info on things I have noticed if this helps any of you experts out there. The light seems to come on shortly after filling up a fresh tank of gas (roughly 25-30 miles into the tank).
-Matt

Any updates Matt?

Yup...the light came on 25-30 miles after fill-up just yesterday.

I don't remember if I left the ignition on while refilling, but I'm going to reset the light again...and see what happens.

[mcw323is]

Any updates Matt?

Yup...the light came on 25-30 miles after fill-up just yesterday.

I don't remember if I left the ignition on while refilling, but I'm going to reset the light again...and see what happens.

Well a couple weeks ago I took it to my mechanic and he said to try the new gas cap thing first. So I got a new cap and it actually kept the light off for 3 tanks of gas.

This past week the light came on again and my mechanic said that its probably gona be the charcoal canister. And the light came on at the end of the tank so who knows...

He said that they have to pull down the whole gas tank to replace that. Is there any truth to that?

[Unicron]

This past week the light came on again and my mechanic said that its probably gona be the charcoal canister. And the light came on at the end of the tank so who knows...

He said that they have to pull down the whole gas tank to replace that. Is there any truth to that?

take down the gas tank eh?
dammit :confused

[jdowpe]

No....this is a valve reachable from the engine compartment.

[speedster]

i had the same problem, luckily 12 hours afdter i bought the car from the dealer so they took car eof it, took them 5 tries and roughly 1200 miles to figure it out but i just had my check engine light come on tonight and i really have a feelign that its goin to cal for the same thing. the thing is the dealer never told me what all they fixed the only things that they told me was that i had over 1000 bucks of free stuff. im goin to go get the code read and find out if i can get all my paper work from the dealer. its amazing that all these people have this problem, b.c when the dealer was trying to fix mine they had to call a tech from bmw noth america for ideas. hmm.

[gasper11]

Hello there,
I figure I might as well add my accumulating knowledge to this subject. I too have been dealing with the mysterious and difficult to solve small leak evap fault code. I too have replaced umpteen gas caps, purchased diagnostic equipment, and so far have replaced the purge valve itself. I have reset the service lights, but expect it to light off again within 50 or so miles. I've been dealing with this situation through three smog control inspections, and have learned a few tricks along the way. However, I still don't know what the problem is... Next I will be tackling the hoses themselves. As I drive convertible 328i, the eveap systems is located under the spare tire in the trunk and not too difficult to get to. Because I live in Arizona, I suspect a hose leak. I will keep you informed as a solve the problem.

[RNeil]

As I drive convertible 328i, the eveap systems is located under the spare tire (http://forums.bimmerforums.com/forum/showthread.php?t=360991&page=2#) in the trunk and not too difficult to get to.

Part of it is also above the right rear tire and it is hard to get to. Another part is under the hood and hard to even locate.

[JBFMCAR]

Any more updates on this ever since i did the M50 maniflold.com kit install on my 97 M3 i get it once a gas tank very very annoying let me know first place to tackle on getting this fixed.

Justin

[CrazyCoder]

Any more updates on this ever since i did the M50 maniflold.com kit install on my 97 M3 i get it once a gas tank very very annoying let me know first place to tackle on getting this fixed.

Justin


I had this code on my 323 from day 1 of purchase. I eventually tracked it back to the expansion tank located in the passenger rear wheel well, you have to remove the finder liner to get at it, but it's not that hard. There is a large vacuum line at the top that tends to break off. New tanks have better reinforced nipples, so it shouldn't happen again.

If you got the code immediatly after a M50 manifold conversion, I'd suspect a broken or improperly connected vacuum line in the engine compartment first.

[JBFMCAR]

Yeah but what hose i would imagine the only one it could be that would set this off is the one from the Charoal canister to the maniold nipple on the opposite side of the manifold to the TB but all these hoses are band new so it doesnt make sense.

Justin

[davew0670]

I had this code on my 323 from day 1 of purchase. I eventually tracked it back to the expansion tank located in the passenger rear wheel well, you have to remove the finder liner to get at it, but it's not that hard. There is a large vacuum line at the top that tends to break off. New tanks have better reinforced nipples, so it shouldn't happen again.

If you got the code immediatly after a M50 manifold conversion, I'd suspect a broken or improperly connected vacuum line in the engine compartment first.

did you replace this? if so, do you have the part name or number? or how to fix?

[CrazyCoder]

did you replace this? if so, do you have the part name or number? or how to fix?

Yep, been about a month and a half with no CEL now. :D

The expansion tank was part 16131183056, it's just called "Expansion Tank" on the part list, according to realOEM.com. I ordered it from Pelican Parts since the dealer wanted $110 and said it would take 2 weeks.

[mzmtg]

Yep, been about a month and a half with no CEL now. :D

The expansion tank was part 16131183056, it's just called "Expansion Tank" on the part list, according to realOEM.com. I ordered it from Pelican Parts since the dealer wanted $110 and said it would take 2 weeks.

Were the cracks in the tank nipple(s) visible?

I'm about to order one to deal with the same issue on my 323is.

RMEuropean and ECSTuning both have the tank for around $65.

I remember reading a post about someone just putting epoxy over the cracks in the tank nipple. If the cracks are visible, I'll probably try that before ordering a new part.

[davew0670]

Yep, been about a month and a half with no CEL now. :D

The expansion tank was part 16131183056, it's just called "Expansion Tank" on the part list, according to realOEM.com. I ordered it from Pelican Parts since the dealer wanted $110 and said it would take 2 weeks.


thats awesome. where exactly was the crack? is it visible? weve been hunting this thing forever and hopefully this is the cause of cel.

[CrazyCoder]

Were the cracks in the tank nipple(s) visible?

You could say that. It was broken off completely.

[mzmtg]

You could say that. It was broken off completely.

I'm getting the "small leak" code. So, hopefully, mine aren't completely broken off yet.

[onetrillionrpm]

I would try getting them to smoke test it, its really simple to do, and will effectively find the leak!

[CrazyCoder]

I would try getting them to smoke test it, its really simple to do, and will effectively find the leak!

Smoke test is a good idea!

Down here, at least, it's not something I've seen offered as a way to find an issue. Seems like most 'mechanics' just want to throw parts at the problem. But a well stocked shop should have the capability to do it, if you ask.

[The Airman]

Hi everyone. New guy here. Just thought I would add my findings to this common problem of the DTC code P0442.

First, about me:
This is my second M3. My first was a 1998 E30. One of the first in the country. Bought back in 1987. It still lives on, and is internally immortalized by the owner of this site. And it can also be seen here at bimmers.com/m3.

My second M3, the current one, has been a great, almost trouble free car for 84,000 miles now. It is the Luxury Edition and over the years I have bought just about everything Bekkers sells for it. Yeah, I did the water pump thing for it, but almost trouble free......... until now.

Last month the Check Engine Light came on for the first time. A quick check with my Trusty OBD II code reader said "P0442". So I bought the factory gas cap, reset the code, and off I went. Until 1 tank of gas later, and I was pulling up to the exact stop light that the light went on before at. It was almost uncanny how it happened at the same place, the same light, right after driving a while on a full tank.

So after a few days of expensive internet searches on company time revealed nothing, I came across this thread using the search term " bmw part 16131183056". The search " P0442" basically came up dead.

So here is what I found, and I hope it helps others.

This seems to be a common fault for the E36, just like the dark spots at the top of the speedo and tach that seem to come and go. So like the other posters before my in this thread, I decided to pull the fuel expansion tank (part # 16131183056) and just check it out because the light was driving my crazy. Sure as shoot, the large hose nipple was cracked just like others have said. It cracked just at the end of the brass insert. So a trim to realoem.com/bmw and $90.00 later I had my new expansion tank with the reinforced hose nipple. So far It has fixed the problem, and the CEL has stayed off.

Here is a fast "how- to" write up for the DIY Hack mechanic.

Remove the passenger side rear wheel. Remove the plastic shroud at the rear of the inner fender. It is installed with 2 10mm plastic nuts. Use caution with these and don't over torque them when reinstalling. The expansion tank is installed with 2 10mm plastic nuts also. You might have to remove the 1 plastic nut that secures the tank filler tube to the bottom of the car to get enough wiggle room to get the expansion tank out. Next cut the 3 clamps off the hoses that go to the tank. It is easier to cut them were you can see them at the bottom, pull the tank out, then remove the hoses from the top of the tank because sometimes those permanent hose clamps can be a pain. Next take off the gas tank pressure sensor. No need to disconnect this. It just pulls straight down off of the tank and is held on with 2 little pins. Some light prying with a small screwdriver might be needed, and it will just hang there. Install in reverse by putting the hoses on the top of the tank first. You can use either small hose clamps or nylon zip ties.

Hope this helps people with that STUPID trouble code P0442.

[neptronix]

Sorry to dig up an old thread but i figured it is better to add to an old one rather than start another new one.

I replaced my gas cap recently, which was the original one that came with the car. This code did not come back on for another 40 ish miles. I just bought it and need a smog certification. Frustrating.

A local shop did a smoke test and found nothing. Does this pressurize the tank and shoot smoke out somewhere? I can't see how it *wouldn't* work if so. Any suggestions?

[DoWnAqT]

update: so i tried to retest HOPING that it'll pass smog after driving about 100miles and HOPING that the code will disappear. Didnt happen...luckily this testing station offers free retest for failed test. so i zip over to the dealer and explained my situation. the reply i get from the tech was that most of these stations dont know how to test BMW's. "you have to run the engine hard until it gets really hot for sometime. keep the rpms up and bring it in immediately, not letting the car cool off and then test. it'll pass then, it happens all the time" (btw, smog test at the dealer is $145 + $140 labor). so to me that didnt sound right but decide to give it a shot..run the 101 for about 15mins, bring it back and the smog tech was kind enough to run a readiness test, car not ready to test yet. the tech turns to me and says that dealership is full of it. so now he tells me to pull my car out of the test stall, he pulls his car in (99VW Golf), runs smog on his car, takes my paperwork and proceeds to PASS mine using his car! Shhhh....i went for a walk and wasnt there to witness it. off to the DMV, all registered now..hmmm?

something to revisit in a couple of yrs??!?


I wouldnt post it on the internet that some guy helped you out by putting his car on the test for you. That is illegal, So I wouldn't post to highly of it. Its cool that he helped you out, so don't say what kind of car he has or where he works, he helped you not everyone on the internet... I help people out all the time to but mostly just my friends with certain situations. Anyways if you have a gross leak code...most of the time its a loose gas cap, A gas cap being loose lets a large amount of air into the system making it the largest leak you could have. So everyone that is saying that it cant be a loose gas cap is clearly wrong. A small leak on the other hand could be something like a gas cap gasket or a burr in the filler neck/ or rust on the sealing surface. But it could also be a gasket leaking on the fuel tank sending unit. My car I found that the pin for the fuel pump got hot and melted the plastic. Allowing air to get in there and fuel to come out causing a fuel odor. I fixed mine and no problem since. But there could also be valves sticking that purge the system and what now. It could be a very easy fix, for very complex.

[neptronix]

I got the car back from the shop today. they have no answers for me :/
Pretty frustrating. They pressurized the system and it held pressure.

They did not look under the seats however.
I peeked underneath. while jiggling the hose on the passenger side rear tank, i could smell fuel, but the hoses did not seem wet or cracked.

It did seem like i could move the hose quite a bit.

are these the nipple fittings that commonly break off? if so, do i basically just need a new fuel expansion tank, or whatever the heck these things are?

and how the heck do you get those clips off, just stick a flathead screwdriver in there and twist?

passenger side:

http://neptronix.ath.cx/fuel1.jpg

driver's side:

http://neptronix.ath.cx/fuel2.jpg

any ideas? maybe i'll move this to a different thread since this one was stale to begin with.

[neptronix]

update.. hopefully someone has any info..
is it possible at all that the fuel filler neck could be to blame?

I have bought two gas caps already, one aftermarket, one BMW genuine part.
Both of them seem a little loose when fitted to the filler neck.

also both of them get a good bit of wet fuel on the bottom edge of the rubber ring.

[neptronix]

Ok, i have an update. and i hope this actually helps someone.

A local shop smoke tested and successfully held pressure in the fuel system, and couldn't figure out the problem at all.

i took it to a BMW specialist and they replaced some $85 charcoal canister valve.

Replacing the valve on the charcoal canister seems to have solved the problem. While hanging out with 'Evil Spoonman' we passed the 45 mile mark that completes the evap system test, and it showed as completed. No check engine light. I don't understand why this fixed the problem. But it did.

If evap leaks aren't evident under the seats, or in the area underneath the passenger side rear wheel well, this could be it. There is more evap stuff that can be broken in the front of the car.

[ricerocket86]

Its really not that hard to find. Go to a shop, have them hook up a smoker to the evap fitting, and smoke the system. Wherever there is a leak, you will see it.


Ok, i have an update. and i hope this actually helps someone.

A local shop smoke tested and successfully held pressure in the fuel system, and couldn't figure out the problem at all.
.
I posted too late, never mind

[kinghawk]

This link may help you a bit... http://forums.bimmerforums.com/forum/showthread.php?t=1151643

[neptronix]

um.. i made that thread, dude :)

[bubbasbeammer]

Just Adding To The Questions Here. I have a 98 328i with 98,000 miles on it and the "P0455 Gross Evap Leak" code set off my check engine light. Like the rest of my fellow bimmers I purchase a new gas cap. (I need to invest in BMW gas cap stalk) I have now checked the hoses going into the charcoal canister under my spare tire and I pulled the tire and fender liner off the rear passenger side and the tube going into the expantion chamber looked fine. But, is it the tube going into the bottom of the expantion chamber that everyone keeps saying is the one that brakes? Cuz I didn't pull the expansion chamber away from the car(because it was attached to the gas inlet tube) to check if there was any other hoses going into it that might have been cracked. All the hoses and plastic still lookes new and fresh. What should I do next? PLEASE HELP!

Ok. Here's the update. (To answer my own quetion... Unless you have an inspection mirror, you do have to take the expansion tank out of the car. If you do have a mirror you could inspect the top of the tank from the gas door. But it would be better to remove it from the car. To do that you have to take two nuts off the the gas filler tube, along with the other steps guys have posted on this link. One of the nuts is up by the inlet, the other is down under the car. Then you can move the expansion tank far enough down to inspect the hoses and fittings) So all the hoses, fittings, and tubing all look to be in good condition on and around the expansion tank. gasper11 said that he replace the purge valve. Is that on the engine or on the charcoal canister in the trunk? Now what?

Ok. I'm an impatient person so I went ahead and through an $88 dollar guess at it. On one of the other forums they were advising a guy to buy a new fuel purge valve. So I went to the dealership (cuz everyone said that was a dealer only part) and baught a "13-90-1-744-150 FUEL TANK BREATHER". It's up in the engine compartment inbetween the mass air flow sensor and the intake manifold. There's a gainplug in the top that you have to unplug, then a funny lookin hose and fitting on the side that you have to push the little C clip lookin thing in all the way then pull the hose off the side. Then, after eating some spinach, you have to pull, and pull, and pull until the last hose comes off the bottom of the purge valve. I then cleared the codes so I'll just wait and see now. I read either in my chilton's manual or on the internet that after the codes are cleared that it can take up to 80 miles of drivng before the system does a test or something. I don't know. Maybe I just made that up. But either way I'll make another post in a few months letting everyone know if it worked or not.

[AgentHubcap]

Is there any way to test the charcoal canister before replacing or removing it? I looked at it today, but I don't know what to look for...

I'll be pulling the fender liner this weekend to see if I can see any issues with the expansion tank.

[AgentHubcap]

Is there any way to test the charcoal canister before replacing or removing it? I looked at it today, but I don't know what to look for...

I'll be pulling the fender liner this weekend to see if I can see any issues with the expansion tank.

[Marv17]

i wonder if anyone has solved this issue?

[brice017]

I had similar issue there buddy,

had the system fogged.

Turns out I had a bad pvc (pressure regulating valve) valve as well as old rubber lines that were going bad.

I also had to replace an emissions item that is located down deep on the driver side strut tower (think this was an electrical item). Can't recall what it is and quick search online is not helpful.

[shogun]

Similar problem here, my wife just complained again, check engine light on and the Peake tester tells me FE large EVAP leak detected.
Sometimes I got a small EVAP leak warning.
When refuelling the car the ignition is definitely switched off. I found that the small leak came from the fact that the fuel tank cap was not tightened properly, so I told here to tighten it always properly. Will check with another fuel tank cap, but the comments so far here are not that optimistic that this will solve the problem.
Will also check the hoses around charcoal cannister, there I might be more successful to find brittle hoses, I hope at least. Will take a while till I have tested and see if the CEL light comes back, but maybe someone meanwhile has found a solution?

First simple step: I used lube oil and sprayed it onto the tank cap gasket, just to make sure it seals good.

So far no CEL light on, but have to wait a few weeks.

Bentley manual page 160-4 says:
Fuel tank evaporative control system
the control system is used to vent the fuel tank to a charcoal cannister, which is then purged by the engine vacuum during normal engine operation. This controls emission of raw hydrocarbons (fuel) to the atmosphere. A fuel tank, located under the right rear fender traps overflow fuel and incorporates extra fuel tank plumbing.
Starting with 1996 models, OBDII standards require that the fuel tank evaporative control system be monitored for leaks. This is accomplished using the fuel tank pressure sensor, the vent shut off valve, and the evaporative purge valve.
On most early cars 1992-1995 the charcoal cannister is in the engine compartment. On later cars, the charcoal cannister is under the spare tire in the trunk.

Unfortunately nothing in detail mentioned about the fuel tank pressure sender, how to test, how to measure, where it is located,or I missed it in the Bentley?

[Vividkid82]

To locate a smaller leak on the evap system, you really need some type of automotive smoke machine...

478574This is the kind I have...about $1200 bucks..

If you don't have one it may be worth it to take it to a shop and have the system checked for leaks before throwing a bunch of parts at the evap system.