Upgrading your 1988 Beretta to Speed Density (Eliminating the MAF) Last Updated: October 27, 2005
If you have a 1988 Beretta with a 2.8L V6, you might notice a MAF sensor in your engine bay along with the MAP sensor. This is because the 88's were setup to sense engine load and map fuel based upon both of these sensors as opposed to just the MAF sensor -- why you ask? The system used on the MAF cars was problematic and sometimes trouble codes were incorrectly indicated. Anyways, to upgrade your car to be 'Speed Density' which will delete the MAF and use only the MAP sensor, you will need to do the following:
Locate and install a PROM (memcal/chip) from a '89-'90 Beretta (to avoid issues with your EGR - auto or manual shouldn't make a difference)
Remove your MAF sensor (it was robbing power anyway)
Splice in an IAT sensor from most any other year Beretta model (they're pretty much universal in the GM world) in place of your MAF sensor.
Wire the IAT sensor up to the black/red and black/pink wires you cut the MAF sensor from. The other 3 wires are no longer used and can be taped off and put back into the wire loom. On the IAT sensor, there will be a black wire and another colored wire -- the black is the ground, so wire that up to the black/red wire. The other wire is for power and you'll want to wire that up to the black/pink wire.
That's all there is to the upgrade. If you're having trouble locating a suitable PROM, your local GM dealership should be able to help them out -- just let them know what you're trying to do (there were service bulletins out about this). Ratings from GM show a 5hp increase in 2.8L equipped vehicles from 1988 to 1989 -- most would say that the MAF delete is the reason.