I have a 1983 cadillac coupe deville with a ht4100 digital fuel injection engine. I have had two people look at my car and say i need a complete tune up, i have had the car for two years and believe it was due for a tune up anyway. I was just wondering what all should i get replaced and how much does a complete tune up usually run.

spark plugs, wires, maybe a map sensor and o2 sensor. also check under your distributor and make sure everything is cherry underthere (ignition module etc)

probably in the 200 dollar range if you want to do it yourself. i just did the plugs on my caddy and checked to make sure everything was working right. some of the plugs are a pain to get to but its well worth the hassle rather than to have a mechanic charge you 300 bucks just to put some stupid plugs in.