I own a 99 Camry LE, 2.2 L engine with approximately 116k miles. In early June, my check engine light came on and I took it to amechanic(one man operation) I had been using for approx six months based on a referral. He had replaced the timing belt/water pump in February, did a good job, and charged a reasonable price. So, I took my Camry to him for the "check engine" light, was charged $184.96($96.79 for the part, $81.64 for the labor) to replace a defective Vacuum Switch Valve. I drove twenty minutes down the road and the "check engine" light came on again. Took the car back for the second time and he said the problem was two hoses he had crossed mistakenly(no charge). Drove the car twenty minutes down the road and the "check engine" light came on again. Took it to the mechanic a third time and paid $123.99($77.45 part, $41.31 labor) to diagnose and replace a Vacuum Valve. I asked him the obvious question, that is, did the first part really need to be replaced? He said it was part of a process, whatever that meant and I agree, part of process that's going to put me in the poor house and cause me to pull the last few hairs I have on my balding head. Got in the car, got twenty minutes down the road, the "check engine" light has come on for the "fourth" time. I've left a message on his answering machine to notify him we needed to talk about this thing. So, here I am, $300 plus poorer, with a "check engine" light that won't go out and a mechanic who has made three failed attempts to repair the problem. What is the likelihood that the parts he replaced actually needed replacement? And do I take another chance with this mechanic and throw more money into the black hole? Any words of wisdom?