I asked for a diagnosis of a check engine light. The first answer cost about $100 ...'it is the crankshaft positions sensor, unless it is the computer.' I asked that the next diagnosis be made for another $100 - definitely the computer, was the answer.
I was given a price of >$800 for a new computer, so I took the car home. I noticed that the notes showed a code of "9", which is NOT a crankshaft sensor, but a cylinder position sensor. I checked again with the guy at the front desk, who reiterated that it was a crankshaft position sensor, but the root cause was the computer.
I followed the manual's problem solving instructions and found the problem to be a distributor. Just to be thorough, I bought both a $150 computer and a $150 distributor. The computer did not fix the problem, but the distributor did.
Bottom line, I paid about $210 for a faulty diagnosis. I would have paid at least another $800 to fix the wrong problem. Then, it would have cost me another $300 for a $150 distributor to fix the problem.