My check engine light went on. I took it to the dealer and was told I needed a camshaft position sensor and serpentine belt. They also replaced a side marker bulb and performed a brake fluid flush. $1125 later the engine light comes back on when I drive it home after picking up the car from the dealer. I take it back the next day and they say there are cam correlation faults in the system and suspect timing chains are stretched causing the failure, to the tune of $3700! Had they found this the first time around, I would have never spent the $1125. Does all this sound right?