also i wanted to add that my 1992 chevy runs really good and when i bought it, it needed a cap and rotor button really bad there was some kind of oil or something inside the cap, also i replaced the plugs.the emissions test was done before the tune up, does a bad cap and rotor button and plugs make a car fail emissions on the nox gas,can a car pass emissions with a egr not functioning properly.is there any way to rig the egr valve just to pass emissions.help!!!!!!!!!

 

Obviously you hit "Post new topic" instead of "Reply to topic" on your other thread.

High NOx is due to high combustion temps or pressure. Excessive spark advance can cause it, otherwise it's all the EGR system.

See your other post for the rest of the story. This one is bye-bye.