emissions!!help me!!!

so i failed my emissions test i had a hc reading of 303.7 @2500rpm and the limit is 220.0
They did a 2500 RPM test instead of a Dynanometer is it easier passing on the dyno or the rpm test? i have a new cat and keydiver chip and 91oct gas at 10psi and no safc, will 87oct with the boost turned down help or should i wait and get a safc? any help would be appreciated.

 

[Sr71sss]

you should post your test result sheet to be of any help to others

 

[Vman911]

when were your plugs changed last? wires?

 

[ktmrider]

Guy had same problem in this thread click lots of good advice and how he passed HC in the end.
Yes, 87 octane is a good start plus some timing adjustments but check out the ( as usual ) great suggestions from DialCaliper.

 

What are your fueltrims doing? How old is the O2 sensor? Does your car smoke much?

 

i don't have a clue what the fuel trims are i have one of your chips and fpr set at 48psi and i don't know how old the sensor is /ubbthreads/images/graemlins/dunno.gif the car doesn't smoke much just a little black puff when on boost im going to try tomorrow on 87oct and no boost and see what happens,should i do the 2500rpm test or the dyno?

 

[ktmrider]

BFP at 48psi is pretty high, that is why Keydiver is asking about the fuel trims. The black smoke at tip-in also points to it.
Drop your BFP to 38psi, run a few gallons of 87 octane, crank the boost down as low as possible, get the car up to operating temps by driving for a good 30 mins, then re-test.
Make sure to purge the 87 completely before returning to the "normal" or previous settings.
EDIT, I removed the "High HC = rich" statement from the original post after more knowledgable folks pointed me to some good references. You can get high HC readings from being absolutely pig rich ( has to do with stoic and lack of oxygen ) but it would rear up in other areas.

 

[FlyingEagle]

Quoting derekvr4:
i don't have a clue what the fuel trims are i have one of your chips and fpr set at 48psi and i don't know how old the sensor is /ubbthreads/images/graemlins/dunno.gif the car doesn't smoke much just a little black puff when on boost im going to try tomorrow on 87oct and no boost and see what happens,should i do the 2500rpm test or the dyno?



There should be no argument as to whether or not your car is tested via the front/rear roller setup or if you have a 2500 RPM test, because your drivetrain dictates what they can or can't do to test your car. If you have an automatic AWD setup, such that it can't be turned off, or you don't tell them you have a selectable drivetrain )), then you have to perform the 2500 RPM test and boost won't be a factor. If you car is FWD, then you use the rollers to perform the test, as this is the mandate, and auto AWD/4WD is the exception that means they run the other test. Take the advice given above, run the 2500 RPM test (boost is not a factor at such constant low throttle ~2500-3000 RPM).

 

[Dialcaliper]

Ditto above - you're running too rich. The dyno test is actually much harder to pass than the 2500 RPM test because the engine is actually under load instead of just spinning freely.

For starters, turn your fuel pressure down to stock for the test (36-38 with the vacuum hose disconnected, 27 with the hose attached at idle) - that will lean you out a little. Double check your O2 sensor if you can. Also, verify the base timing (5 degrees BTDC at idle) if they didn't already at the emissions place.

Dump a gallon of denatured ethanol from the hardware store in the tank along with a full tank of gas to lean it out.

Basically, too much CO or HC (unburned hydrocarbons, ie fuel) means too rich, and too much NOx means too lean.

If you're going to attempt to use 87 octane to pass with no SAFC or timing control, remove the wastegate actuator from the turbo completely so you don't get into boost driving around.

 

Actually, his chip is burned for 550's and 48psi base fuel pressure. But, injector flow varies, and underhood pressure gauges are very inaccurate, so I always tune the base fuel pressure by checking the HIGH TRIM. What brand 550's are they? Do you have an adjustable FPR? Do you have a fuelpump upgrade? Is it rewired? Without knowing what your TRIMs are doing it is very hard to help you.

 

there rc 550's and a warlbro 255 pump, i dont think it was rewired and yes iv got an adjustable FPR its set at 48psi just like you told me /ubbthreads/images/graemlins/smile.gif i should have a safc by the end of the week will this help me much?

 

[Sean92AWD]

Check you timing. Mine was -10 retarded and i didnt check ti till after i went to emissions. I then turned my base fuel down to 20psi and it cruised right through.

 

Quoting derekvr4:
i should have a safc by the end of the week will this help me much?



Without a logger an AFC is rather useless, because you are tuning blind, IMHO.

 

so i went in today for a retest and failed big time- I turned down the boost and turned down my base fuel pressure to 28 PSI and used 85 octane gas and drove the car for 45 minutes before the test, these were my readings- HC PPM @ 2500 RPM = 706.2 and at idle = 352.9. The limit is 220. What can I do now?

 

I took my car to the Broomfield location and they did a full dyno test on mine. Hmmmmmm. Although, my results we're represented in GPM, grams per million?

I scored .49 GPM HC with a limit of 1.5. 5.2 CO with a limit of 20. MY co2 was 387 with no limit shown. NOx was .744 with a limit of 3.5. Would the broomfield station measure differently?

 

[Dialcaliper]

Relating a personal experience, my car (when it was running) failed a couple times when I had it tested at the cheap shop - they had to do a bunch of weird stuff to even get a reading like sticking a rag in the exhaust tip and rerunning a couple times. (it kept coming up with "dilution").

Then I took it to a nice clean emissions test place where the guys seemed like they knew what they were doing, and more importantly, their equipment looked to be taken good care of, and the car passed with flying colors on the first run, no monkey business or anything. Granted, it cost almost twice as much, but compared to the headaches involved with failing the test, it was worth it.

Sounds like GPM might be "grams per minute" instead of just parts per million, which is something they could conceivably do on a dyno and not with just a tailpipe sniffer.