Question Asked: Spark Plug Gapping Creating Unburned Fuel Fail Smog
June 05, 2010, 11:01 PM
Check engine light is on, OBDII scan not helpful at all, fails emissions when ran at 2500 rpms 200 HC's where max allowed in CA is 130. Was told might be impropper plug gapping but we use pregapped plugs. O2 sensor is fine, found could be Exhaust Gas Recirculation Valve Replacement needed but info there says would fail for high NOx, we fail on HC's ...what else could it be?