Quote Originally Posted by Bio248 View Post
if you matched every single wire and put a two position switch with a bank of relays in there you could easily swap between the two and the car would never be the wiser.

however, it's sounds like a super pain in the ass.

Not really, just run the wires to the pcm for the engine control side and leave the rest with the original PCM. Just a CEL is permanent.

But a Megasquirt PCM would be easier to hook up I'd bet.