I seem to remember a post once that said bad spark plug wires could cause an extra load on the ecu. If you still have the original wires it might be worthwhile to get a new set. In your case it could also have just been the age and miles on the unit. Several folks have had to repair/replace the ecu recently--the 3 electrolytic capacitors get old and start leaking acid on the circuit board, next thing you know, it fries or dies. Mine fried, so I bought a used one from a junkyard, I replaced the capacitors as a precaution. So far, so good. Keep us informed of what happens, and good luck.