So the saga continues... the mechanic replaced the camshafts, big $$$. Two days later the engine light comes on again. We scanned the codes and it's a #5 cylinder misfire again. I talked to the shop owner and he tells me it's a bad valve and the head needs replacing now. Now i'm not a mechanic but how was the bad valve missed? He told me it was because there was a bad lifter on that cylinder before the repair. Does that make sense? I'm worried now to go ahead with this in case it's actually a bad cylinder.