Ok so a friend of mines is having problem with his 2000 Honda Prelude. The CEL came on and later found out it was the TPS sensor. We replaced it and disconnected the battery and the CEL is still on. So we borrow another one and the CEL disappears. So im thinking it the ECU that's going bad.

BUT my question is can i just get another ECU and plug it up? Do they have immobillizers? Is a 2000 Prelude OBD2A or OBD2B?

I told him to just get a conversion harness and chip a p28 to his car spec.
I know that it wont pass emission with the conversion harness and ECU.

What's the best thing to do before taking it to HONDA and spending crazy money?