I have a 93 camaro Z28 that I've done a lot to lately and I had to have a smog check done today and I failed it badly.

The reading said on the HC (PPM) that I measured a 1203 at 15pmh when the max is 83 and a 1038 at 25mph when the max is 48.

The CO (%) measured 0.91 at 15mph when max is 0.48 and 1.01 at 25mph when max is 0.46.

The O2 sensors are new, new fuel filter, new EGR valve and the small vacuum line for it. New Eddelbrock shorty headers, Cleaned/recharged K&N cold air intake, new catalytic converter, new spark plugs and wires, new coil, New Optispark GM Distributor with new cap and rotor.

I ran the test for a blown head gasket and that came back good. What else could it possibly be????

There are no other modifications such as a chip on it either.

PLEASE HELP!!!???!!!

 

Sell it and buy the one in my sig. You'll pass with flying colors.

 

Why would I buy the same exact car.

 

Mine passes emissions with flying colors?

 

Modifications?

 

start with the basics - is the car is a good state of tune?

 

I think it stinks that ALL states don't have the same emissions testing program we have here in Michigan.

Michigan has the best Emission and Safety testing program in the world for non-commercial vehicles; absolutely ZERO !!!!!

VERY friendly to gearheads and hot-rodders

 

you don't happen to have a different MAF sensor in it do you?

 

93' is speed density...There is no MAF...

 

How many miles????? Headers....HHHmmmmm Do you still have the smog pump??

 

Your most likely suspect is ignition. If your engine is running crappy, your emissions will be higher. How is your car running overall? Any signs of a misfire or hesitation?

I would check your whole ignition, start with the wires. You said new wires are in there, make sure you didn't cross any to the wrong cylinders. Check your plugs and make sure they are all tight, check for any arcing. That's what I would start with, good luck tracking that down. Damn those emissions standards!

 

AMEN! I'm sick of being strangled with emission testing + restriction after restriction. Are state lines invisible borders to pollution? Why does one state get clobbered while even neighboring states get to skate?

 

No modifications other than theparts listed. As for it being the ignition, that all has been completely replaced from the wires, plugs, coil, module, distributor, cap & rotor. I've double checked and nothing has been crossed up.

The engine runs great now, that is why I was confident when I went to smog.

I found a addative product that claims a guarantee to pass smog when used. Anyone know about that?

 

You said there is a new cat on your car. Is it a stock replacement or a high flow? Any chance it could be defective or gutted? Just throwing things out there...

 

Its a magnaflow universal cat.