I have a 96 LT1 vette with high mileage on it (150K) and recently it has started fouling the plugs on the passenger side. The car has ran great all its life, and within the past 10K miles it has had a new distributor and ECM. The car started missing and coded for an O2 sensor which I replaced (replaced all 4 since I was in there). At the same time I decided to do the plugs. When I replaced them I noticed the passenger side was fouled (same side as bad o2 sensor) and now about 200 miles later they have fouled again and the o2 sensor is coding again. The driver side plugs are fine. I've checked the engine for vacuum leaks and didn't find any. The ignition system on this is mostly new and the O2 sensors are new, so is there anything else that I should look at? Are there any other fuel or ignition components/sensors specific to the passenger side that could be malfunctioning without throwing a code? Thanks

 

Welcome to the forum.

Might do a compression and leakdown check. Check injectors on that bank also.