I just did a diagnostic check on my 1986 fleetwood brougham. It came out as a code 34, which I believe means "map sensor too high." I was trying to find out what this meant, someone mentioned something about the exhaust pressure? Well I recently purchased the car minus muffler. Could this be whats causing the engine light to come one?

Im not sure exactly what the MAP sensor does, and if you dont get an answer within the next couple of days, post "bump" in this thread and someone will help you!!

The MAP sensor is the "Manifold Absolute Pressure" sensor. Per the Haynes repair manual, "The Manifold Absolute Pressure sensor monitors the intake manifold pressure changes resulting from changes in engine load and speed and converts the information into a voltage output. The ECM uses the MAP sensor to control fuel delivery and ignition timing." Hope that helps. I don't think that the vehicle running without a muffler would affect the MAP though. But I could be wrong.

Ok..... I get the MAP and the MAF confused a lot..... :)

Id say you need to replace the MAP..... Muffler wouldnt have anything to do with the MAP readout......