axel523

93 Civic EX, D16Z6 naturally aspirated. Lower end rebuilt bored one size over. Has header instead of stock exhaust. Took to get inspected high HC 400 should be less than 200 to pass. New cat, new injectors, new plugs, new fuel pressure regulator engine timed by my mechanic who incidentally replaced all the other items to no avail. Mechanic said it was temperature related. every time cooling fan would come on the HC would jump up. He relocated the O2 sensor to the end of the header collector. Wrapped the header, he said that would solve the problem. Not so sure, anyone else had a similar problem.

lazlong

Did you tell the inspector the true size of the engine? It does make a difference.

What kind of cat did you use? Did you use a "hi-flow" cat? If so, get a real cat and put it on for the test then put the hi-flow back on afterwords.

Or, you need to check to see if the HC's are going high when you turn other things on. That means there's probably something wrong with the charging system (alternator).

Also, check for codes: http://check-engine-light-codes.blog...retrieval.html

axel523

stock cat, no codes. will check the charging system.
thanks