I've had this '98 Saturn SC2 for a couple weeks and it'* been running fine. Just today it started stumbling on heavy acceleration in 4th and 5th gear. It wasn't setting a CEL, but I put my AutoXray scanner on it, confirmed it wasn't setting a misfire code, but then brought up "Operational Data" while the engine was running. Under that information it was showing misfires on Cylinder 3 (no other cylinders). Any ideas.... I'm thinking maybe a bad coil pack? Normally a misfire on 3 would set a CEL of similar to a P0303 or the like?

it might have a time period or number of misfires it hasent reached yet. check easier stuff first. move plug to different cyl see if misfire follows. try wire then if not try coil pack swap. inspect for terminal corrosion while you are checking. i am assuming they have the coils like on the 6cyl that plug into the icm. if that doesnt help post back and we can get into deeper causes