Hello! I'm not the one fixing it, another family member has been. It has a 307 engine in it and we've had all sorts of issues with it and it now comes up with the check engine light on and gives a code when you even just turn the key to the accessory position. The error code states that it is a PROM error, and he just recently installed a new computer for it. We've checked everything to make sure it is okay and its all supposed to be, yet we get that error. Where exactly could we buy a new PROM? Is this an issue we'd need to take to a dealer?

What is the number of the code? The service engine soon light should come on briefly after the ignition is turned to indicate it is working. The ECM will always flash a code 12 before any other codes. The code 12 indicates the system is working properly. If it is throwing any other codes, please list the number. Thanks.

Well, I will ask what the code was tomorrow. He's going to inquire about the PROM to our favorite place, Grossman Chevrolet in Burnsville, Minnesota tomorrow. I do know that the car has ran unbelievably rough the last 4 months or so and we haven't driven it in forever because of it. Basically, if he backed it down the driveway...we probably wouldn't get it back up without pushing it back up. He did say that the error code that gives back 'Bad PROM' or something similar comes up consistently, whether the car is running or just on accessory.

I can't even begin to describe the amount of troubles that 307 Y has given us lately. He said a few times he was ready to just give up entirely, but that its worth going on. He could get a truck, but it wouldn't get anywhere near the gas mileage that station wagon gets, or he could get the Magnum...which doesn't hold as much and "looks ugly." :) We asked around to places in the area and none had what we were looking for (apparently--I wasn't the one doing it).

From what I hear, it sounds like the PROM is probably the source of the problems he's been having the last few months.

I had very rough running condition in my 88 Trans Am. Mechanic had diagnosed it as bad computer. But he said it was good to put in a new prom as well, which is a circuit board which plugs in near the computer.
I think he charged $90 for the prom, and he got it from a Chevy dealer.
New computer and prom solved the problem.