So my 06 Cobalt SS has been throwing a misfire code for a while now. We had the spark plugs changed but it didn't get any better, so we took it in. They spent about 8 hours trying to troubleshoot today. Had all the spark plugs changed, all the coils swapped out, etc. What they finally found was a regular missed spark event every 50-52 sparks, like clockwork. They gave me the car back tonight at no charge. Said I should take it into the dealer as it might be a PCM issue.

I was wondering if anyone else had come across a similar issue. Or had any questions I should ask the mechanic. I'll get as many details tomorrow as I can including codes and what they tried to swap out. I'm trying to collect as much information as I can so I can get the dealership to honor the warranty they told me would "cover everything that's not wear and tear or routine maintenance". They've been difficult in the past -_-