Have a 1994 Chevy Caprice wagon that just failed the HC emission test .82 allowed and came in at .89. Is there any additive or suggestions on getting it to pass. Has about 133k miles with original cat coverter, distributor cap, and ignition wires but plugs were changed about 20k miles ago, the car has been sitting without being driven for about 3 months so will take it for a good hard drive. have heard that adding a few cans of dry gas or alcohol will help? have been using regular octane gas and also wonder if premium would help or hinder test results.
Failed emission test
Jul 12, 2003
3 Replies
I might just remove the air filter for the test - and fill up with premium gas if that will help. how about boosting the temperature by blocking part of the radiator??
A dirty air filter will raise CO levels. High HC is caused by a lean misfire.
Chris
change the oil & filter too....
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