Have a 97 Cavalier with p0300 (random misfire) and p0172 (rich fuel condition).I'm assuming the rich fuel condition is a result of the un burned fuel hitting the o2 sensor post catalytic converter? anyhow, had it on a scan tool that reports cyl 1 and 4 are missing intermittently. Changed plugs/wires and the coil pack for 1&4. Still missing.on 1&4 Changed ignition control module. Still missing on
1&4.... What tells the ign control module to fire the coil pack? Crank position sensor?
When looking at graph on scantool (Modius Snap On) while attached to plug wires shows (on 2&3) like EKG blips (even height spikes with flats between equal spaced). On 1&4 Some full spikes some half height and some flats where even spacing would indicate spikes should be. (yeah, not the correct terminoligy, but I'm doing the best I can...)
I'm about $280 into parts that I didnt need... Anyone got an idea?