Passed CO etc ... HC's were 378 with a limit of 220. This year they made me rev to 2300rpm and hold. Previously it was an idle only test.
Line was very long and the cats probably cooled down. Any tips and tricks beside heating the cats with a hard drive? Would a dirty MAF matter?
Set-up is an AA Rotrex c30-94 intercooled kit, and I tested with AA's standard tune.

Passed CO etc ... HC's were 378 with a limit of 220. This year they made me rev to 2300rpm and hold. Previously it was an idle only test.
Line was very long and the cats probably cooled down. Any tips and tricks beside heating the cats with a hard drive? Would a dirty MAF matter?
Set-up is an AA Rotrex c30-94 intercooled kit, and I tested with AA's standard tune.

I used to own a Massachusetts State emission center that did enhanced emission testing up until 2001..until I sold out..
IIRC.. "HC" would be spark plugs or weak spark....or ignition ( which we really do not have except coils...( no wires or cap)

Cats would be "NOX"

And O2 sensors or fuel control would be "CO".....

"CO and HC "together being HIGH....you would bring "CO" down first THEN see what the "HC" look like ....

But since you only have "HC", I would look at the plugs , plug gap and /or coils....

Please post the complete emissions test report.

Not much information to post.
Test = measured/limit; HC = 387/220; CO = 0.46/1.2; CO2 = 13.9/NA; no test of NOX
I've had a suggestion that the O2 sensor could be bad, but it passed CO by better than half the limit.

Not much information to post.
Test = measured/limit; HC = 387/220; CO = 0.46/1.2; CO2 = 13.9/NA; no test of NOX
I've had a suggestion that the O2 sensor could be bad, but it passed CO by better than half the limit.


It is not the O2...read my post...if you please..:)

I saw your post, hence my comment on the CO. I don't think it's the o2 sensor either.
Before I do anything, I am gonna warm up the cats and re-test. I barely drove the car prior to getting in line, then just sat there and idled.

I saw your post, hence my comment on the CO. I don't think it's the o2 sensor either.
Before I do anything, I am gonna warm up the cats and re-test. I barely drove the car prior to getting in line, then just sat there and idled.

What do you plugs look like? including gap?

You are experiencing either misfire or a lean condition. First check the ignition system (including the plugs as mentioned previously), then chek the injectors. You may want to run some fuel injector cleaner through it to help with any possible buildup or blockages. Make sure your fuel pressure is correct as well.

I am having occasional misfires when moving quickly from a coasting idle to +25% throttle when under 2000 rpm. I'll pull the plugs tonight. I've run some cleaner before. Do you recommend a particular brand?

Change your oil, also.

Change your oil, also. ? :confused What's the relationship? I am running Castrol GTX 15w40 (OE) and BG addative, btw.

Wouldn't a high HC count indicate a rich mixture with the cats not operating efficiently? Although the low CO points to it not being overly rich.

Wouldn't a high HC count indicate a rich mixture with the cats not operating efficiently? Although the low CO points to it not being overly rich.

I have had cars at my shop that failed for NOX with passing HC and CO...
I normally found HC that was slightly "failed" was ignition or spark plug related...

? :confused What's the relationship? I am running Castrol GTX 15w40 (OE) and BG addative, btw.

I can't explain it but its a long time fact that if your car is sloppy in emissions that changing the oil, since you naturally burn a little bit of oil especially in our cars, with new oil with no traces of carbon or anything can and will help your emissions.

I have had cars at my shop that failed for NOX with passing HC and CO...
I normally found HC that was slightly "failed" was ignition or spark plug related...

Yea, I could see that. NOx is from running lean or low catalyst efficiency.

I saw your post, hence my comment on the CO. I don't think it's the o2 sensor either.
Before I do anything, I am gonna warm up the cats and re-test. I barely drove the car prior to getting in line, then just sat there and idled.

Thats why you failed, cats weren't hot enough. Be sure to put some decent miles on the car before going in for the smog. I recommend a 50 mile road trip.

Thats why you failed, cats weren't hot enough. Be sure to put some decent miles on the car before going in for the smog. I recommend a 50 mile road trip.

Not correct. He did a two speed idol/tsi test. The cats have little corralation with HC and CO's. While a good cat can help with lowering HC and COs, its really not going to help. We have seen cars with no cats pass a tsi test with very low CO/HC numbers. Cats are used to lower Nox which are not tested in a tsi test.

I am a state inspector in Texas and a lot of the information in this thread is simply wrong. We recommend checking/replacing plugs, then checking/replacing coils and/or wires when someone fails for HCS. You will also want to check if you have vacuum leaks. High HCS are going to mean you are running rich for whatever reason or the computer thinks you are incountering a rich condition. Check these items in this order.

1. Plugs
2. Coils/Wires
3. Vacuum Leaks
4. O2 Sensor

Its a bit different with a boosted car though. Are you running bigger injectors? Do you have a wideband? Try doing the test at home and see what kind of A/F ratio you get on your wideband.

I would change plugs and gap properly, and heat your cats up more before the test just for good measure. I've had cars with cold cats produce odd results period.

Ok ok. Lets bring it down another level.

HC = Unbunt fuel from the get go.

CO = Burning fuel and air that went out.

NOX = Over 1500*f

What burns fuel = Air + spark.

Check those 2 items. If you don't have alot of air, your running rich. If you can't light the air and fuel mixture your ignition system isn't up to pair.

Also the CAT on a vehicle will help reduce most readings but not by alot.

P.s. The only change thing does work. It has helped me.

Not much information to post.
Test = measured/limit; HC = 387/220; CO = 0.46/1.2; CO2 = 13.9/NA; no test of NOX
I've had a suggestion that the O2 sensor could be bad, but it passed CO by better than half the limit.

Assuming you have good, properly gapped plugs, no vacuum leaks, working 02 sensor, your cats were probably just not hot enough. Even if you barely drove the car beforehand, and it sat for a while at the smog shop. I posted my previous comment because I had the same problem recently with my M3 back before it was S/C. I borrowed a set of fresh cats and put a good 20 miles on them before I brought the car in. It barley passed HCs at idle.

Not correct. He did a two speed idol/tsi test. The cats have little corralation with HC and CO's. While a good cat can help with lowering HC and COs, its really not going to help. We have seen cars with no cats pass a tsi test with very low CO/HC numbers. Cats are used to lower Nox which are not tested in a tsi test.

I am a state inspector in Texas and a lot of the information in this thread is simply wrong. We recommend checking/replacing plugs, then checking/replacing coils and/or wires when someone fails for HCS. You will also want to check if you have vacuum leaks. High HCS are going to mean you are running rich for whatever reason or the computer thinks you are incountering a rich condition. Check these items in this order.

1. Plugs
2. Coils/Wires
3. Vacuum Leaks
4. O2 Sensor

Its a bit different with a boosted car though. Are you running bigger injectors? Do you have a wideband? Try doing the test at home and see what kind of A/F ratio you get on your wideband.

Well we have something in common because I have a CA SMOG license.:thumbup: And from my own personal experiances with my own M3, I have encountered that these cats need to be extremely preheated before an emissions test. Call it whatever you want to call it, I just think that the OP should put some decent miles on the car before he starts replacing various parts in order to shotgun his cause for his failed smog. Saves money and it gives the cats a shot. Maybe the cats are bad? Maybe they just need to be driven? Maybe he does have a spark or A/F issue?

Just finished changing plugs to NGK; Changed to Mobil1 15w50; Cleaned MAF; Used some injector cleaner; Quick test drive showed the low-rpm miss is gone; Plugs looked lean (white); Stupid Bosch Platinum 2's (stupid is as stupid does)

Just finished changing plugs to NGK; Changed to Mobil1 15w50; Cleaned MAF; Used some injector cleaner; Quick test drive showed the low-rpm miss is gone; Plugs looked lean (white); Stupid Bosch Platinum 2's (stupid is as stupid does)
plugs white means you are too lean, plugs wrong (too hot range), low octane, timing not set properly. You might want to pick up a wideband and tune it more. I alwats go a little richer when you want to pass emission.

You are experiencing either misfire or a lean condition. First check the ignition system (including the plugs as mentioned previously), then chek the injectors.

I am a state inspector in Texas and a lot of the information in this thread is simply wrong.... High HCS are going to mean you are running rich for whatever reason or the computer thinks you are incountering a rich condition.

:confused

Just finished changing plugs to NGK; Changed to Mobil1 15w50; Cleaned MAF; Used some injector cleaner; Quick test drive showed the low-rpm miss is gone; Plugs looked lean (white); Stupid Bosch Platinum 2's (stupid is as stupid does)

I hate to say 'I told you so', but...

Yay you changed the oil

do you think it was the plugs or the injection cleaning?

plugs white means you are too lean, plugs wrong (too hot range), low octane, timing not set properly. You might want to pick up a wideband and tune it more. I alwats go a little richer when you want to pass emission.

This is false.

White means he is lean.. but not "too lean" at all. Pull a factory plug after running the car 100 miles and it will be bone white (if the car is running properly). The "hot" indication is not the porcelain coloring at all, but the discoloring on the threads of the plug. You want between 4 - 6 discolored threads, less can be a sign of too cold, more is too hot. Timing again has very littler impact on the color of the porcelain. To tell what your timing is doing, you should look at your ground strap. You want there to be a line or "band" right about half way through the radius of the bend of the ground strap. Its hard with our cars as we run such variable timing but to check this you should set your timing advance fixed and cruise and see where the line develops. The further toward the threaded portion, the more advanced you are. You want it to be right around the center of the radius. Octane won't change the color of the plug either - you can have a nice clean 1 lambda cruise on C23 or 87 octane... if you run leaded fuel you might see deposits, but otherwise no change in porcelain color that can be used as an indicator.

</sparkplugrant>

I haven't re-tested yet, so let's not all get excited. Spooltime, I'll take your "I told you so's" all day long. Just keep giving the great advice. For the testing, I put in AA's tune, so I can't make it richer (encrypted bin). Oil looked good, but changed it anyway. #5 cylinder had some oil around the plug, but I don't feel like changing the valvecover gasket yet. MAF cleaner can't hurt, plus, I don't trust this K&N filter. I'll update after I test. I'm driving about 25 hard miles to a test center that won't have a long line. Maybe today maybe tomorrow. Raining and warm today, does that make a difference?

Just finished changing plugs to NGK; Changed to Mobil1 15w50; Cleaned MAF; Used some injector cleaner; Quick test drive showed the low-rpm miss is gone; Plugs looked lean (white); Stupid Bosch Platinum 2's (stupid is as stupid does)
Update: passed
Test = Retest/First test/limit
HC ppm= 13/387/220
CO% = 0.01/0.46/1.2
CO2% = 15/13.9/NA; no test of NOX
I put some miles on it before I tested but still sat in line for 20 minutes.

You're welcome... ;) Glad you passed!

You're welcome... ;) Glad you passed!I would say plugs was the number 1 culprit. The other stuff couldn't hurt.
I am surprised at the difference in HC's and CO compared to the original test.

I would say plugs was the number 1 culprit. The other stuff couldn't hurt.
I am surprised at the difference in HC's and CO compared to the original test.

Exactly! High HCs, mostly likely means you need new plugs.

Thanks steevieweevie and welcome. Get that post count up so you can have some fun.

Turn your A/C on...trust me :)