I failed the CO and the HC part of the emissions test in my 89 standard hatch. All I had done before the test is a new air filter and plugs.

Since then, I've changed the cap, wires, rotor, oil, o2, fuel inejctor cleaner, and cleaned the tb.

I also put in 91 octane fuel ontop of a 1/2 tank of 85.

I've been reading that I should retard the timing, and I've also been reading that I should advance the timing.

I've read that the high octane can be bad, and I've also read that the injector cleaner can be bad.

Should I retard or advance the timing? Should I run this tank dowen and put some 85 octane in it, or try it again as it is?

 

damn, 85 octane up in the hills, we get 87 here as the lowest....i'd try some gaurentee to pass stuff and possibly if you're up for it something to remove carbon deposits, not sure how much it helps but a cleaner engine is a friendlier engine

 

I can't find the GTP stuff anywhere around here

 

Empty your tank completely. Fill it with 91 octane OR higher if available. Advance your timing as far as possible unless you start to hear it ping or (dentonate). Although your fuel might not be the problem. Go to c-speedracing.com and read up on how to check codes because I dont want to take the time to explain it, then if it DOES throw some codes recheck the meanings on the very same c-speed site. Basically what im getting at here is you might have some bad sensors which would cause you to fail. Let us know how that works out for you.