Porsche 803 3.5" HFM is NOT entirely plug and play.

[MIKe30]

Just getting this posted on the internetz for everyone else that will run into the same issue I did for the last 2 weeks. The porche bosche 803 3.5" HFM is not entirely plug and play.

OBD2 applications have 4 prong connectors at the MAF. There are 2 grounds, black and brown/orange. On the stock MAF the ground pins 1 and 4 have continuity and are essentially the same point. On the Porsche HFM, the ground pins 1 and 4 do not have continuity - they are open. You MUST get continuity between these points just like the stock MAF. Doesn't matter where you do it, so it doesn't necessarily have to be on the pins where they plug in. I did it in the wire harness leading up to the plug.

Spliced mine together this morning and voila, no more jerky car when started, no more bucking bronco feeling when trying to take off, no more stumbling idle that shuts the car off, no more table 11 code 08's. Nice and smooth now from the get. Was very very very happy to finally figured this out after getting some help from a fellow member (Matt). Unfortunately everywhere I searched I could not find the solution to the issue, luckily he chimed in on one of my local threads here.

Writing this up to help future obd2 guys. Hope this helped, good luck!

[Stück]

AFAIK this was common knowledge.

[bmwpowere36m3]

AFAIK this was common knowledge.

+1 Also doesn't it have a different "scaling" factor or whatever, so you need proper software to run it as well.

[BadBoostedBmwM3]

So, you are saying that the OBD-2 won't just plug into the 803 maf without problems??

I actually did not know this. I knew the obd-1 had to be modified.

[luikang325i]

is this good for obd1 with 803 maf ? OBD2 [COLOR=blue !important][COLOR=blue !important]applications[/COLOR][/COLOR] have 4 prong [COLOR=blue !important][COLOR=blue !important]connectors[/COLOR][/COLOR]

at the MAF. There are 2 grounds, black and brown/orange. On the [COLOR=blue !important][COLOR=blue !important]stock[/COLOR][/COLOR] MAF the ground pins 1 and 4 have continuity and are essentially the same point. On the Porsche HFM, the ground pins 1 and 4 do not have continuity - they are open. You MUST get continuity between these points just like the stock MAF. Doesn't matter where you do it, so it doesn't necessarily have to be on the pins where they plug in. I did it in the wire harness leading up to the plug.

Spliced mine together this morning and voila, no more jerky car when started, no more bucking bronco feeling when trying to take off, no more stumbling idle that shuts the car off, no more table 11 code 08's. Nice and smooth now from the get. Was very very very happy to finally figured this out after getting some help from a fellow member (Matt). Unfortunately everywhere I searched I could not find the solution to the issue, luckily he chimed in on one of my local threads here

[Matt]

+1 Also doesn't it have a different "scaling" factor or whatever, so you need proper software to run it as well.

Very different.

Here is the problem with the 803: On OBD2 cars it plugs right in but it needs electrical modification. On OBD1 cars, the plug doesn't work (you can "modify" it) but you don't have to do any special splicing.

Either way you need software programmed specifically for the 803. It is NOT the same as a euro/540 3.5" MAF.

[MIKe30]

AFAIK this was common knowledge.

well it must have been so common that during a search it didn't pop up on any site I checked, and in my box from bimmerworld no instructions came with anything. Now common knowledge or not, the next idiot that tries to straight plug and play it will be able to find this thread and not spend a few hundred bucks troubleshooting like i did.

[cuuloco10]

FYI ...TMS has an adaptor for the Porsche MAF - I got it a couple of years ago and was in the ballpark of 70 - 100 dollars.

[Alpine346]

Like me, not that im the idiot, lol, but i sure as hell have had massive problems with my 803 meter, and have found no help until this thread. Including calling turner motorsports, asking them why the hell my 803 meter isn't working, saying the code is saying short to ground, and why it's not working with my software. And they had no answers for me except, reinstall the software! So Thank you very much Mike30 for this thread!

[beteljaws]

Thank you very much Mike30 for this thread!

+1

[CMG]

AFAIK this was common knowledge.

It's common knowledge that anytime you switch out a MAF for a different element or size, software is essential for proper tuning.

[beteljaws]

It's common knowledge that anytime you switch out a MAF for a different element or size, software is essential for proper tuning.

Software is common knowledge. But connecting the two grounds together on the 803 isn't.
You would think the vendors that sell the 803 in a kit would tell their customers what to do or include some instructions.

Greg

[Alpine346]

Agreed! I have the correct software, that was obvious, the wiring part is not. Every single vendor who sells the 803, or says you need the 803 to work with their software, say it's plug and play. It's very much not, and now my car is running great because of this post!

[MIKe30]

Glad you guys are getting some use out of this thread. Wish it was around when I first started troubleshooting the bitch!

Agreed! I have the correct software, that was obvious, the wiring part is not. Every single vendor who sells the 803, or says you need the 803 to work with their software, say it's plug and play. It's very much not, and now my car is running great because of this post!

[jworms]

can you further explain what you did to get it to work? and this is not the "Euro/540" MAF? is 803 the last part of the part number on it or something? i'm curious if i have the porsche MAF and maybe this is why my car has never run right with it...

[bennyfizzle]

IIRC 803 is the last 3 digits in the part number....that and it'll have a porsche insignia on it...I am not at all sure of that and I have no experience on the matter as I have the Euro 3.5.

[Matt]

can you further explain what you did to get it to work? and this is not the "Euro/540" MAF? is 803 the last part of the part number on it or something? i'm curious if i have the porsche MAF and maybe this is why my car has never run right with it...

What is the part number on your MAF, what car is it in and what kind of software is it running?

[jworms]

IIRC 803 is the last 3 digits in the part number....that and it'll have a porsche insignia on it...I am not at all sure of that and I have no experience on the matter as I have the Euro 3.5.

What is the part number on your MAF, what car is it in and what kind of software is it running?

turns out i have the Euro MAF:


and i have AA software that has never worked for me in combination with the MAF

[Matt]

Is that on your OBD1 e36? Or on your OBD2 M3?

Either way, running with your MAF unplugged is stupid.

[jworms]

Is that on your OBD1 e36? Or on your OBD2 M3?

Either way, running with your MAF unplugged is stupid.

obd2 and i understand that it's not ideal, but it's better than the alternative right now.

[InuFaye]

I have the Euro MAF and for some reason I keep getting the code thrown for MAF. It looks like the PO never installed the turner wiring adapter.

[Uliman]

FYI ...TMS has an adaptor for the Porsche MAF - I got it a couple of years ago and was in the ballpark of 70 - 100 dollars.

does the TMS adapter solve the Porsche HFM continuity problem described and fixed by Mike?

[uta0929]

does the TMS adapter solve the Porsche HFM continuity problem described and fixed by Mike?

Yes it does.

[dinanstu]

turns out i have the Euro MAF:


and i have AA software that has never worked for me in combination with the MAF

Check back with AA to see if they have a tune for the Euro MAF, if not Dinan does.

[Uliman]

Yes it does.

thank you; that is what I thought and just wanted some kind of confirmation! looking to do StII soon; just need the HFM (803/809); 24 lb injectors (Ford Mustang on Ebay); TMS adapter and the software!