[Oldsguy]

Programmable Read Only Memory. If there are revised PROMs that addressed the carb running too rich that might be a solution, if you know what version your PROM is. If yours isn't one of the later versions then you might be able to correct the problem with the newer PROM. But, it might not be available. If your PROM wasn't working most likely the engine wouldn't run at all, as Joe said, they usually don't fail and if they do the just go. I bet the PROM in your car is doing exaclty what it was programmed to do. Remember what Joe said though, sensors give the computer data and if any of them are giving faulty data then the computer can't do it's job corrrectly. Lots of variables to look at before buying something like a PROM, I bet they aren't cheap.