I posted here several months ago about check engine light in my 1996 Ford Explorer coming on (61,000 miles). Finally found the problem.
1st time light came on -Ford Dealer changed all spark plugs.
2nd time -Ford Dealer changed one spark plug.
3rd time -Ford Dealer reset the computer.
4th time -Ford Dealer changed one spark plug.
5th time -Ford Dealer changed thermostat & radiator cap.
6th time -Ford Dealer changed OS sensor.
7th time -Ford Dealer said head gasket was blown.
Took it to a different Ford dealer & they said head gasket was blown. Left it to be repaired. When they took it apart the heads on both sides were cracked. I bought this vehicle new and babied it all its life.
Contacted Ford Motor Company & they said since it was out of warranty & there are no recalls for that problem there is nothing they can do. I think the heads were defective when the SUV was built or the dealer that I purchased it from created the problem by not finding the cause of the check engine light coming on to begin with.