d#mn emissions

I have checked everything possible from the haynes manual for emissions failure for my 94 Z except for the catalytic converter. I replaced some vaccum lines and the egr valve and still almost the exact result on the test. Any suggestions? by the way it is a california car but now resides in IL. Thanks.

so you need to check the cat still? if u do...here is what u can do. first ...hit it...if it rattles its shot. second...if ur able to get ur hands on a temperature gun or some way to get the temp from before the converter and after the converter. before the converter should be at least 100 degrees hotter than the back of the converter. at least thats how we check em at work cause our other machine is always broke.