My Brother in Law has a ~2001 Chevy Impala with the L36. it's had a random misfire only on cylinder 3 and, only at wot. he has tried new spark plugs, new coil packs - oem, new plug wires, swapped injectors around, he changed the ICM wire harness, hollowed out the catalytic converter, and probably tried a few other things I don't remember, only thing he hasn't done is a compression test. could an upper/lower intake manifold gasket cause the failure or a warped upper intake manifold? just trying to run through the list of possible causes before he get's rid of the car, or before I offer to buy it cheap as a top swap candidate.
is it a random misfire if it is only on one cylinder?
Originally Posted by markpa
