Hello, my 92 Camaro is now registered thanks to the help of a few of you guys. The front end I got fit great. The tach fix (network resistor) worked awesome!! The problem is that I failed emissions and want to fix the emissions system so I pass. I am having problems finding what to check and in what order. If someone is a MA state registered emissions repair tech or just had there car fixed. Please let me know what to do or what you had done. Now for the specs, I passed back in 06 and have made no changes. I have a 305 TBI with a chip of unknown origin. I got readings of HC(idle) 0628 limit 0220, CO%(idle) 0226 limit 01.20, HC(2500rpm) 0581 limit 0220, and C0%(2500rpm) 02.39 limit 1.20. I want to fix my car not cheat the test. I looked at other threads and only found was to "beat" the test. Looking forward to your help and support as this is the best 3rd gen site out there.

 

It has been my experience that in order to pass the test your CAT must be in excellent shape. Once I changed CATs I never failed. Start with your exhaust system.

In Illinois if our cars are older than '95 we don't have to take the test anymore...yea.

 

Well I am No Expert for MA rules However all states are pretty much the same...Number 1 Check your Converter Make sure you car is ran atleast 30 minutes before it's tested. DO NOT shut off your car in the testing lines the HOTTER your converter the better your test will be. Only shut if off when they tell you to.Make sure You have fresh gas in the car. Also make sure your Gas cap in on good Or you will toss a EVAP Code and you will NEVER PASS. They should of givin you a sheet, on the sheet it should say at what point you car did not pass..I am talking abought the graph..Also make sure you have had a good tune up some what close to the testing sometimes even a fowl plug will fail ya....Good Luck ! Is your Check Engine Light On?

 

Ok, I'll look at the cat and do a tune up. Any one got a way to test other the taking it in and paying the 29 bucks? Any other things any can think of to check. Thanks for the help guys.

 

Correct me if I'm wrong, but evap codes didn't come along until OBD2 in 96, there for, the gas cap wouldn't come into effect on a 91,except for it being on the car.

 

no my dads van faild the test do to the gas cap and his van was a 87

also i to would like to know what all whould help pass the test cause i have to take it soon and it faild last time i we just got a weiver but since then the cat has been replaced but i dont know if that is the full problem

 

well check your evap system, the pcv valve, EGR valve, Cat of course and do a basic tuneup: oil, plugs, wires, etc. I'd start with making sure your EGR works first, when you have the car running, reach up under the EGR and push up on the diaphram with your fingers, you should hear the engine idle change, if you hold it and the idle stays at a constant change then your egr is good as far as vaccum goes, it might be gunked up too, the only way to look for that though is to pop it off and look

Good luck, hope it works out

 

you've gotten some good advice so far, i'll add this.

from the numbers you gave, its running rich. check it for any codes.
a few things that can cause you to be rich are,the motor not getting up to full operating temp.
a weak O2 or dead sensor.
if the O2 sensor is old, it wouldn't be a bad ideal to replace it. use only a A/C Delco O2 sensor, other sensors just don't cut it.
any exhaust leaks from the manifolds to about a foot or so after the O2 sensor can cause the ECM to think the motor is lean & make it add fuel. check the AIR injection system, it should not be directing air to the manifolds once the motor is warm.

95 & older don't set codes for the eavp system, but most states that have emissions testing do pressure test the gas cap.