Does anybody know if you have to swap out the ECU on a 99 cavalier with a 2.2 and a 4 speed auto when you do a manual transmission swap? I've heard the ecu with from the factory works, but I've also heard I need to swap out to an ECU from a manual cavy. Can anybody help me out? Thanks

Hope is not a plan. Change is not a destination.

I'm not 100% sure either way. I know when i did it on my 1995 sunfire, i did switch the computer, because i found one on ebay for $20, exact same year, and everything. But, i know the Automatic, which i had the mechanical 3 speed, had a safety built into the wiring where the wire which went from the key to the starter, went through the transmission, so i had to connect those two wires where they used to go into my transmission to get my car starter to work.

I would think the fuel tables and other items are the same, and the auto ecu might work after swapping, but you'd need to see if that safety check is just a wire, or if it goes through the ECU, which would mean you would have to swap it out.

You can run the auto ECU, but you will get codes for the auto tranny not being there. Also idle will be lower. If you have HPT you can change most of this. It will run fine with the auto tranny.



FU Tuning