Buy yourself a OBD2 Scanner for your car and stop paying a mechanic or shop
You can pick up a OBD2 scanner on amazon for $20-$30. When your check engine light comes on, plug it in (usually under the steering wheel) and scan for error codes. When you get the code, you can get more information just by typing in that code with your car make and model into google. More than likely someone had the same issue with your car model. This will save you so much money in the long run because many of the repairs can be done just by looking it up on youtube. A 10 minute video ends up saving you hundreds on repair bills.
Remember, the only difference between you and a Mechanic is knowledge. The knowledge is now free, use google and save money on simple repairs. For those big jobs, you can hire someone to do an exact job instead of them telling you what needs to be fixed.