I started my 2003 F250 Ford V10 eng with 105K miles. One owner, looks new. The check eng light came on and stayed on. I took it into the Ford place here in Yuma and 3 hrs later they said I need a new ...
Generally if the check engine light comes on, the computer is working fine. You might want to buy a code reader at Harbor Freight and learn how to read it (very simple). This way you will know if the repair facility is trying to scam you.