Ok guys......i have a 1992 Firebird, 305 V-8 L03 TBI motor, and have been trying to pass emissions testing here in (Illinois), here are my reading for the 3 tests i have done so far.

1st test : Reading Standard Result
HC 1.86 0.80 Fail
CO 31.9 15.0 Fail

2nd test : Reading Standard Result
HC 1.54 0.80 Fail
CO 17.2 15.0 Fail

3rd test : Reading Standard Result
HC 1.52 0.80 Fail
CO 15.0 15.0 Pass


so far i have put on a new......rotor/cap/coil/ignition module/wires/plugs.....cat back exhaust system........the only other thing i can think of is the catalytic converter and O2 sensor are bad..........my A.I.R tubes are still connected and not rusted or busted off and my emission numbers have gone down since adding all the new stuff, so what else could it be if i invest in a new cat and O2 sensor and still cant pass, my car doesnt show any codes on it and runs fine.........any help would be appreciated......thanks

If you want to be sure to pass next time, those are two good candidates for replacement.

Another good idea is to change the oil just before you go for the test.

Find "the emissions" guy ask around w/ the Sat. night racers. There is always a guy for a few C notes will pass ya. I have no emissions in my car (I mean my friends car) and "he" always passes, out $150 but who said hot roddin' was cheap?

I have seen people just change to a new cat and it has made a world of difference. By the way, where in Il are you? Up by Chicago?

Ben

Have you considered trying some of the fuel additive bottles in your local auto parts store? Some of them claim a money back guarentee to pass your emmissions tests and some of them actually work. I know the brand called "emissions pass" works. Just something to consider.

well I have already done my 3 ..free.. tests allowed by the state for my car........guess i'll have to suck it up and put on a new catalytic converter and see if that helps make it pass......and yes im just south of Chicago and north of Kanakee about 45 mins.

I am down in Decatur. Luckily we dont have emissions tests down here.

Ben

register your car in another county that doesn't have emissions

MINE FAILED DUE TO ME PUTTING A 160 STAT IN. AFTER I PUT IN A 195 IT PASSED FINE. THAT WAS THE ONLY CHANGE I MADE.

that is true; its why gm made these cars to run so hot, because a hot running engine has cleaner emissions.

Let your car heat up and run before you go for emissions, i was having the same problem with mine. my hc's were at 1.67 when i went the first time and i didnt let the car have a chance to warm up. I took my car to my buddys shop and we threw there equipment on it and found no trouble codes or nothing. So the 2nd time i went for emissions i let it run for about 30 min before i went and i passed and had .3 hc and that was that. Dont go and spend the money on the cat if u dont have to it is a waste.