Emissions test=Failed!! HELP!

[MahFiVeOh]

I just had an emissions test done today and my car failed!! The readings were ....

HC ppm Limit=66 My reading=58 PASS
CO% Limit=0.37 My reading=0.01 PASS
NO ppm Limit=0757 My reading=1834 FAILED!!!

Idle readings all passed.

Now i need some help as to where to start looking for my problem.I had new headers and H pipe installed before winter so i doubt it is an exhaust leak.My car has 165xxx kms on it and i change my oil every 3-4000 kms so the motor is still running ok in my opinion.Just curious where should my timing be set at for a basically stock 5.0L?? From what i saw it looks like it is at 12*( is each line on the balancer 1 or 2 *?? )I run 87 octane gas 99.9% of the time.I'm on a tight budget at the moment so i need to get this fixed asap without spending tons of $$ PLease help

Oh did i mention emissions testing sux!!


Thanks

 

[mustanghunter50]

find someone who will just give you the stickers without the test

 

[MahFiVeOh]

Thats pretty hard to do around here in Ontario.I have to bring the sheet with the data to the Ministry of Transportation in order to get my plate sticker.

 

[89SaleenGT]

NOx is way up. timing for a stocker should be set about 8-10°BTDC with spout removed.

Car sitting at idle passes.

OK,

Set the timing then check the EGR if it is working.

If the car was on a rollers a cause of excessive NOx is a non-functioning EGR.

 

[vristang]

First thing to do is pull the codes from the computer.

I would suspect that your egr system comes up.

jason

 

[65ShelbyClone]

Oh did i mention emissions testing sux!!

Yeah, tell me about it. That's why I got the the '68(pre-'75 is exempt here). Too bad I have to get the SVO checked; they're usually hard to get to pass.

Since NOx is the only thing that went too high, I also suspect an EGR problem.
Sometimes a rich condition will make the cats burn too hot and raise the NOx, but it also elevates HC and CO. Both of those were low for you, leaving pretty much the EGR.

 

[MahFiVeOh]

 

[ej95cobra]

With NOx high and everything else fine it means your cylinder temps are high. I had the same problem in PA.

HC limit 0275; test = 175 passed
CO limit 1.10, test - 0.05 = passed
NOx limit 3600; test = 4270 - Failed

Car may be running lean. You could plug the vaccuum to FPR, that will increase fuel; but may throw other measures off. Also as noted above, you could retard the timing. I went to 7 degrees timing and plugged the FPR vaccuum; measures were:

NOx = 1565 = passed
CO = 1.55 = failed
HC = 570 = failed

Try putting in a lower temp thermostat (160*) to get past emissions. That's what worked for me. I also put timing back to 10*. Here are the readings"

HC = 220
CO = 0.2
NOx = 2530

Good luck.

 

[stangjunkie]

retard the timming and try again still nothing then unplug an injector

 

[vristang]

I am always amazed at the suggestions for passing emissions tests.

Do not un hook an injector.
Do not install a 160 stat. (unless your local weather dictates)

The majority of emissions failures also indicate that something is wrong with the motor.

Fix the problem!
Don't create new problems!

Pull the codes!

jason

 

[65ShelbyClone]

Try putting in a lower temp thermostat (160*) to get past emissions.

Definitely don't do that. It's possible the engine will not come out of warmup enrichment. I suppose that could cool down the combustion temps, but also at the expense of HC and CO emissions. I actually put a 195* in my '89 GT before getting it tested. It had a MAF, headers, and Flowmasters on a 180k engine and never went over half the limit for any emissions. I don't know if I still have the old smog sheets for it...

The only reason I didn't get caught on the shorty headers is because they were Flowtechs that turned rusty and looked stock.

 

[ej95cobra]

The issue is getting past emissions inspection. The 160* will help keep the chamber temps lower thereby reducing the NOx. It will not significantly affect HC or CO emmissions. You can put a 180* or 195* back after passing inspection and spend as much time as you want chasing other causes.

 

[DMAN302]

with cats on the car there is NO reason why you can't pass...pull the codes and set timing at 8deg, leave the spout out for the test.