I must be fairly stupid, but I have seen many of you talking about "PROM's". I have yet to figure out what that is. I have a clue, but I am not totally sure what it is. Could someone please fill me in?

 

A PROM is a chip that you put into your car's computer, in place of the stock chip that controls timing, among other things. People replace these, or burn their own, to get performance gains. Many companies sell them, and they are fairly easy to change out. Mostly (or completely) for fuel injection cars.

 

PROM= Programable Read Only Memory.
It contains the program that actually runs the engine systems.