I am looking to buy a car that has heads cam headers no cats and everything nice and it sat all winter and the battery died, now its running real rich? is that common does it take time to reset or relearn? Does aftermarket tuning affect this?
Thanks Shawn

 

The long term fuel corrections (BLM's) are stored in volatile memory, and will be lost when the PCM loses power. They will start to rebuild as soon as the PCM enters closed loop on the first startup. An individual "cell" can stabilize in a few minutes. The oddball cells, made up of unusual combinations of MAP anf RPM can take a while to stabilize, because you don't spend a lot of time in them during "normal" driving. If the car was correctly programmed for the mods when you put it in storage, losing power to the PCM will not affect it. It should run just as well as it did before you put it into storage.

If you've been driving it for a week, and its still running rich, you need to look for the cause.... exhaust leak, EGR leak, misfires, stale fuel, etc.

Hard to get any more specific than that without knowing the year of the car.

 

its a 96 trans am with a obd 1 conversion and a mad wolf tune