I made a reservation for my GMC truck to be analyzed. I told them the Code p304 that I was getting because my engine light was coming on and off. I was told that I will be charged $160.00 and it will probably take a couple of days. I requested a loaner car.Then I had to request the supervisor to vacuum the car upon receiving it. Service return a call about my truck. I was told that I needed a camshaft at a cost of $5200 that I asked him to list because he said this over the phone. I asked could it be bad coil. I was getting a misfire on number 4 cylinder. I've changed plug, wires!!! What type of diagnostic test do you guys do? AutoZone let you run a test for free, I spent $160 to get the same answer I gave you. WOW, thanks for nothing.