Originally Posted by sseidriver97
First off welcome to the GMForum and i don't understand your question.Are you asking if its is possible to replace a s2 with an s3?Of course anything is possible will it be easy NO it would mean all new computer/wiring harness/pin switching ect ect.It would be much easier to replace it with a s2
Not sure that you are thinking along the right line. Replacing a S2 with a S3 is a lot easier than a S1 to S2 upgrade. Main things that would need changed for it to work in a S2 car: Replace the returnless fuel system with either fuel logs for S2 or use S2 fuel rail (not 100% sure on fitment there), change the throttle body out because the S3 uses drive-by-wire, some modifications to the wire harness, and a tune (possible computer swap but I do believe timing and other things are the same between S2 and S3, once again I'd wait for another member to chime in on that). Those are the main points I can think of right now. Don't have personal experience with the S3 but I have researched a lot on it before.