I have a problem,my 84 Z28 keeps showing that the map sensor is bad or something,i reset the computer and it still shows up,whats goin on,i think i know where its at on the drivers side on the firewall

 

i had this problem this morning and couldn't figure it out, so i started checking things under the hood. what i found was that i forgot to reconnect the weatherpack conncector to the map sensor itself...when i connected it, the code went away. this may not be your problem, but it is worth a shot to check it out.

 

i'm having the same problem in my 89 iroc 305 tpi, it says something about the map sensor having too much vacuum but idk where the sensor is..i'm gonna try to find out where it is and just hope to get lucky whiile switching vacuum hoses

 

On my 91, the MAP Sensor is on the passenger side rear of the plenum.