emissions failure

[lil' red dsm]

just failed my emissions test because the hydrocarbons were almost 4 times the legal amount. my guess is that it's running rich. the blowoff valve is recirculated, so i don't see how that could be the problem. the fuel pump, injectors, and engine/fuel management are all stock. a friend tried checking the computer with a scanner but couldn't get anything out of it. he thinks that the computer might be bad. any ideas?

 

[akdsmer]

CO is rich. HC is a misfire. 4 times the limit is a bad thing. You should repost with all the emission readings just to make sure, but if your CO was okay and the HC was high, your looking at things like dirty injectors, bad plugs/wires, low compression, vacuum leaks (my #1 cylinder intake leak was a bear to find and gave me 2000 ppm HC....).

If your CO was really low, then it could be a lean misfire due to low fuel pump pressure/volume, regulator, dirty injectors or PCM input (like bad MAF). Assuming it is a mechanical misfire, I would start with a compression test, then do a cylinder balance test (remove a fuel injector connector of spark plug and see if you have a cylinder that doesn't drop as much as the rest) and go from there. If you can find a cylinder, you can trade out the injector or plug and see if it follows to the other cylinder. Also propane or brakeclean around the intake manifold. I wouldn't jump on an ECU yet...

Like I said, post all the emission numbers out so we can give you some better information.

 

[DSMcamaro]

We have emission tests in Wisconsin? Hope I don't have to get tested any time soon

 

[jackstandracer]

ok heres a way to make your car pass, ive done it same with everyone in the utdsm.org club, to make it pass what we've done is retard the timing to 0btdc(which requires a timing light) and only do this when your at the emissions place DO NOT DRIVE ON IT LIKE THIS, then gap your spark plugs 2/3times the normal amount, and buy that gurantee to pass aditive. with these 3 things done ive passed my car w/o my cat and emission controls.

 

[95TalonOwner]

On a side note-----You're lucky up in Steven's Point. I think it's only Fond du Lac county and south that need emissions tests. I need to find a friend that has a house up north so I don't need emissions tests anymore.

 

[andytalon]

ok heres a way to make your car pass, ive done it same with everyone in the utdsm.org club, to make it pass what we've done is retard the timing to 0btdc(which requires a timing light) and only do this when your at the emissions place DO NOT DRIVE ON IT LIKE THIS, then gap your spark plugs 2/3times the normal amount, and buy that gurantee to pass aditive. with these 3 things done ive passed my car w/o my cat and emission controls.

Does this really work???

 

[akdsmer]

You still haven't posted your numbers...WTF

Changing your timing 5 degrees and reducing your plug gap isn't going to take away 3000PPM of HC

If your HCs were a little over, the timing would make a change, but the reducing the plug gap wouldn't. The heat of the spark increases as the voltage increases- This would help reduce CO and HC a bit, but involves OPENING the plug gap. This is because the heat created helps to ionize the molecules in the combustion chamber, creating a better burn.
Also, the bottle of I/M passer isn't going to help your HCs either.


Your "4 times the limit" means your HC is somewhere over 3000PPM. This isn't a little misfire, or a timing issue......... but what do I know......

 

[pepsi21463]

Change your plugs and wires, possibly even the coil pack. I had very high HCs which turned out to be a misfire.

 

[jackstandracer]

I swear on it, but like i say dont drive around on the timing set to 0 as for i know what happens =P, just when you get ready to do the emission set the timing make sure you ground the timing plug and set it to 0btdc(guess that would considered TDC though =P) then once tested reset it back to normal then have fun.i passed mine off w/o my cat and my emissions which i was freakin out about.

 

[sandman7000]

check your cat efficieny. take a laser temp gun and aim it just before the cat and right after it. it should be hotter after the cat, bout a 100 degrees hotter. were you able to look at the 5 gas analyzer to see what was goin on. im not familar with emission checks. do they print you off a copy of your test. look at the CO2 levels. that is a efficiency indicator for the cat. it should be about 13 to 16 percent. if not you could have a bad catalytic converter.

 

[akdsmer]

look at the CO2 levels. that is a efficiency indicator for the cat. it should be about 13 to 16 percent. if not you could have a bad catalytic converter.

This vehicle should have 15-15.5%CO when in good fuel control and with a working catalyst. This vehicle in good fuel control, but without a working cat will be around 14-14.5% CO. 13% is poor fuel control and/ possibly a bad catalyst. Not only a bad cat.

A catalyst isn't going to cover up 4X the HC LIMIT (most likely 750 or 1000 ppm), although it could clean up 4X the normal HC output of this engine.

 

[BGGSTin]

With my mods I was surprised, I passed with flying colors. I can't remeber the exact numbers...I think they're in another post floating around here somewhere but my car barely even registered on the meter.
That's no cat...and all the other goodies.

 

[trbotaln]

If your CO and all of your other gases are okay, then most likely you need a new cat.