My buddy just bought a 92 GSR and he is having some problems wit the ECU, according to his mechanic. I don't know much about the older GSR's but I am trying to help him out.

The engine is a B17, correct?
The ECU should be a P61, correct?
Is the ECU located on the passenger side footwell?

He is having a problem with hesitation and stuttering, and the CEL comes on every now and again. His mechanic told him it was a problem with the ECU, but he never even checked the codes. I am a ways away and am trying to get a little knowledge before I see him this weekend. I am also trying to locate a known good ECU to pick up so we can check out the mechanics theory that it is just a faulty ECU that is causing the CEL. The ECU should throw a code if the CEL is on correct?

Thanks for your help, and yes I have searched. Can't seem to get a solid answer on the second two questions.