I got bored in the shop class and decided that i would see how my emissions were doing. so i can do a before and after when i put the new O2 on and fix the FPR. here is what i got


600 RPMS
CO-->.23
HC-->2200
Co2-->6.5
O2-->4.6
NOx-->41

2000 RPMS
CO-->.20
HC-->251
Co2-->10.31
O2-->3.6
NOx-->53

standing behind the car at 2000 rpms it sounds like it has a nasty miss or something. doesn't sound much like a V8 should. sounds kinda raspy or whatever. just doesn't sound right..

also in the mornings or when the engine is cold the car runs VERY bad. it will stall when i first start it. even if i give it gas and rev it to about 1500 when the car first starts it will just die. and if i hold it at about 1500-2000 the rpms will go down to about 800-900 rpms and then jump back up. and then slowly go back down and will eventualy go steady after about 15-20 seconds.. also the engine likes to backfire alot when its cold. so i have to sit there and let it warm up for at least 3-4 min before i can drive (which isn't a problem in the mornings, but when i go from the school to the tech center and i can't let it warm up, then its a problem).. the only thing that was changed really is i got the Injectors cleaned and flow matched. and ported the intake. i installed new gaskets and i seem to actualy have better vacuum now then i did before. fuel pressure is a tad low. about 41 PSI with the hose off. but i don't see how this could cause problems at lower RPMS. especialy the problems i am having in the morning. i am putting on a new O2 sensor this weekend and i am gonna fix the FPR on monday.. but other then that what is my problem? and what can yall tell me about the Emissions readings above?

also, can anyone give me some info about what each Gas is and what systems on the car relate to that gas. and what are good levels for those gases etc. etc.. so i don't have to keep asking

 

Your RPMs are different which could alter the reading. You show overall improvement except in NOx which I think is related to your cat (don't buy a new one 'cause I said that... just a guess). To lower your HCs futher, try a PCV valve. Those things work wonders for such a small device and they're cheap. Your fuel filter should be fairly inexpensive, and may get your fuel pressure back where it should be.

Also, to improve your emissions, run your car like a scalded dog. Go real fast as often as possible, hit 100 on the highway (just dont get a ticket) but run the living shnaz out of your car for about 15 min. Then go test it. Running it hard (and at high speeds for a while) does a lot to blow out crap that makes your emissions high. Ever since I've started doing that, I haven't failed. could be coincidence, but they say to make sure your engine is warm. I make sure my engine will freakin' burn your hand

Retest and let me know if any of that works or if I'm just making stuff up.

 

top

also see http://discussions.gmforums.com/show...threadid=32270 for alot more details

 

top. again