Cadillac Repair: 1987 Cadillac Coupe De Ville, cadillac coupe deville, 1987 cadillac coupe deville

Question
My 1987 Cadillac Coupe Deville (4.1 L engine) (front wheel drive)is slowly losing gas mileage and seems to be losing power.What could be casing this?

Answer
IS or HAS the check engine light ever illuminated on the dash while driving the vehicle ?.

This may sound stupid but you would be surprised how many people are running around with tire pressure way below the specified amount of air pressure that will cause your fuel mileage to suffer.