ok so i finally got the car to emissions after it sitting for a year and it failed miserably. it has a highflow cat and the airpump and egr are removed. it also has the mods listed in my sig. i can put the airpump and egr back on. it failed the idle test. the limit of hydrocarbos was 220 and mine was at 1437. it also has a cheap set of champions in it. also the msd was unplugged at the time. would it help to plug it in? or do u think theres no way of it passing with such bad numbers? anything u guys recommend for emissions testing. like drive the car hard all the way there to get the cat warmed up? stuff like that.

 

What did the numbers for CO and NOx look like?

Neither AIR or EGR affect the HC's. That's usually a sign that its running excessively rich, but there are other possibilities, and knowing all the numbers will help pin down the problem.

 

the co was 1.65 and the max was 1.4 or something like that. i didnt see the nox numbers.

 

Sounds like its running extremley rich, and/or the cat is not working.

 

I'll bet you had the same problem as me when I had High HC.

Check your charcoal canister and the tubes that run to it! Your HC being that high means that the lines are probably clogged and if theyre clogged bad enough they get saturated in fuel over the years. The test we do here sucks all the air in from the exhaust and everythign around it which includes the fumes coming from the leaky canister or saturated lines (or even a bad seal on the fuel tank pump).

Best way to check is to get behind the car after a drive and stick your head under near the fuel tank, and the wheel well.... If you smell gas - thats causing the HC count.

It can also be youre car running rich or a bad CAT(as injuneer pointed out) however GM cat's are $$. If you have a print output of your HC on your test report and theyre bouncing up and down all over the place at low and high rpm (Erratic) then its most likely sucking up fuel from somewhere back there

I went through cat's, O2's, cleaning injectors, fuel filters, etc until finally figuring out the problem. (mine however didnt have a noticable fuel smell from the rear wheel well )

Hope this helps!

 

man i hope i figure this out. thanks for the help so far guys. its really annoying. my car always had a strong smell and i really hope i figure it out.

 

If you've got a gas smell i'd pull the cover on the canister right away as a starting point and just stick your nose down there

Sounds like fumes causing high HC to me, was a bitch to figure out... End result -> Dropped the rear end, replaced all the tubing and the canister.

 

i really hope that it isnt nearly that bad. my numbers were pretty high.