Last time I had the oil changed in my 89, they told me that the size filter I had is no longer available and they put a smaller filter on. Ever since then, the check engine light comes on as soon as the car warms up. The guy still put 5 qts of oil in. I remember this happening once before when the wrong size filter was used. The car was out of commission for a couple years and was checked out thoroughly by a mechanic prior to the oil change. Everything else is ok and I've had no problems. Are the larger filters really no longer available or was the oil guy fibbing? Could the high oil pressure cause the seals to leak? Should I worry?