Flyinrio

1993 stock motor and exhaust. first test failed all 3 (HC, CO, NO). Found out the head gaskets were bad pulling coolant through the exhaust.
Retseted and failed all 3 again but betteer than the first try.

Can it be the exhaust system is so dirty? Autozone did a check with a tool that he said all it showed was code 12. Something to do with the ignition module.


Any suggestions as to where to start?
thanks
Ken

Gideon's_Test

You might get more help if you post this in the C4 forum.

cdkcorvette7

Ask a mod to move this thread.

I can offer that the place that failed you should be able to tell you why you failed... GL

sean.b

wrong section, but if your ignition isnt burning all of the fuel and you're just blowing it out the tailpipe..

best of luck with the c4 owners!

Flyinrio

thanks. I will move thread.
Ken

dougbfresh

Bet the Antifreeze killed the O2's and/or Cats. I "think" the OBD1 12 code used to be the end of system test.