Emissions Help Needed

[VancTalonAWD]

Help, I can't get my car to pass an emissions test. It keeps failing for excessive hydrocarbons, everything else is good. First had it tested with the 680cc injectors, boost at about 15psi, and all the SAFC corrections. Failed Today I put in the stock 450cc injectors, set boost way low, and set the SAFC corrections to 0. Still falied Then I tried again with the SAFC corrections to -4 across the board and it failed again.

The test involves a driving simulation and everything is good on the data they give me except two points where they need to accelerate quickly. Each time when the turbo spools the HC reading spikes, and I mean really spikes!! Thus the average reading over the test is pushed way high and the car fails. Emissions data is listed below:

680cc Injectors
HC Reading=0.86 Max=0.50
CO Reading=5.40 Max=9.32
NOx Reading=0.36 Max=1.24

450cc Injectors with 0 AFC correction
HC Reading=0.69 Max=0.50
CO Reading=7.44 Max=9.32
NOx Reading=0.35 Max=1.24

450cc Injectors with -4 AFC correction
HC Reading=0.59 Max=0.50
CO Reading=6.67 Max=9.32
NOx Reading=0.34 Max=1.24

These are measured in g/km, that's grams per kilometer.
Sorry for the length of this post but I had a lot to cover. Running an EvoIII turbo. Complete list of mods can be found in my profile.
Any help would be appreciated.

 

[calcifer]

New cat maybe?

 

[copper_gst]

Are you running any sort of aftermarket exhast? If you are you might want to put the stock back on for the test. Aftermarket setups flow better because they let more by like in the cat. If not it could be a problem with you egr valve (but that is more then likely not it because it only spikes under hard acceleration). It could be that your cat isn't working correctly. If you want perhaps easy way out there are also a few products on the market to that are suppose to "help you pass emission testing". One of them is PuraGas Emissions Test. It say it is "Guaranteed to pass emission test with flying colors". I can't say if it works but they seem to have data to back it up. There one of their web sites about it.

http://www.protecusa.com/tbpuragas_emissions_test.htm

Hope that helps

 

[VancTalonAWD]

Thanks. I was thinking it might be the cat but the readings are good except under boost. Would a new cat make that much of a difference. The car does have an aftermarket exhaust that was installed when I got it. It's a GReddy cat-back but it's only 2.5inch.

When I biult the engine, I had not heard of DSMLink. But now I'm seriously thinking of dumping the SAFC trickery and going with DSMLink. What do you all think?

Attaching a picture of the detailed emissions report.

 

[VancTalonAWD]

Just noticed the labels got cut off the sheet in my picture.
First Graph=HC Second Graph=CO Tirhd Graph=NOx Fourth Graph=CO2
Last Graph=Vehicle Speed (dotted trace is used)

 

[copper_gst]

DSMLink would help you turn much better then your set up. The catback would not make that spike. I was thinking that you might have had a turbo back exhast. And the cat will make a fair difference in your emissions reading. Hope that helps.

 

[Dark_Horse]

Have you tried using additives like guarantee pass type stuff? I think it's called HEAT. 1 can of that in 1/4 tank of gas and you should pass. I know many people that have passed using just that.

Do you have any boost leaks? How are your fuel trims (I'm assuming ok since you're running 450cc injectors)? Do you have your plugs gapped properly? Are your plugs & plug wires new? All of those can cause high HC. Since your CO readings and NX readings are ok, your cat is most likely fine.

 

[VancTalonAWD]

Plugs and wires are new, but I have not checked plug gap. Fuel trims are are 0 or +2 and I have the SAFC set a little negative about -2 across the board. Should not be any boost leaks as all the piping is brand new and prof built/installed. However, I will check plug gap and boost leaks tonight or tomorrow. Thanks for the ideas!!

 

[BIGBLAZE79]

If all else fails, try and put some denatured alcohol in the tank. You should be able to find it at the hardware store. It's used as a paint solvent. You only need about 1/4 - 1/2 gallon with a quarter tank. It will run kind of crappy. I have used it twice in my truck to get it to pass. I have not used it in my car so if it blows up ...... I'm going to delete this post I have known many friends who have to use it to make there heavily modified cars pass. Or you could take it to a shop that has a sniffer and they will get it to pass.