P0300 Random Misfire after install Mcloed RXT

[Alex5.0]

Hi ,

Did you ever had a customer call that he have a random misfire at low rpm after a clutch change ?

thansk !

[PST]

I have seen that happen at service shops. One I fixed with a crank relearn, another was getting a serious audible rattle out of the clutch, so we fixed that and the problem went away. Then another one just had a vacuum leak and was actually misfiring. The cause was a bad injector o-ring, and the service shop had only changed the power steering rack.

According to gm si, I beieve it was on a tsb I read, out of balance clutch/flywheel/balancer items can cause this code. It even mentioned severely out of balance wheels, lol.

I would start by monitoring the misfire counts for each cylinder. If there is one or two that consistently count upwards, then start with diagnosing why those cylinders are actually misfiring.

If the counts are random across all cylinders, then you may have a junk clutch, bent input shaft, out of balance part, etc.