Wife's 92 Loyale wagon had intermittent check engine light for a couple of weeks then it stayed on. We took it to the garage where tech established it was an "erg" indication. He rest the chip and we drove the car home. On her next use, the light again came on and stayed on. Interestingly, a regional TV station had a segement on with a mechanic interviewee stating that winter fuel additives has caused numerous "check engine light" indicators. What additives and how would it effect the indicator?