A friend of mine took his 2000 Regal to a hack hoping to save a few bucks on a tuneup. He had the plugs and fluids changed. Now the car has a serious misfiring problem, Check Engine light comes on when accelerating. Of course he believes this is a coincidence.
He currently has the car at another garage (not dealer) trying to save a few more dollars. :-) The previous replacement plugs are toast, seriously scorched. The injectors were cleaned and a new fuel filter, but still no joy. The things been under diagnosis for about 10+ hours now, at $X per hour. Apparently the trouble code does not pinpoint the problem and it does not appear to be any given cylinder(s). The current best guess is an intermittent timing sensor.
I told him to take it to the dealer after the first fiasco, but he is convinced that the dealer will just keep replacing parts until his wallet is empty. I would think that experience and the right equipment would go a long way to solving this problem in short order. He will only get hosed by the dealer if he lets it happen.
So how hard are these problems to diagnose? Who's right?