[projectRDM]

I love fail threads.

A manual ECU isn't the only thing you'll need to pass the CEL test. If the original owner didn't wire in the neutral and 5th gear switches you'll still fail since they're part of the OBD-II system and needed to not trip the light. It's rare that people do that since both switches aren't needed for anything else. Check the codes first, if you have either you'll have to hardwire them straight to the ECU. Right now you have a CEL because the auto ECU is looking for inputs that no longer exist, the manual will do the same. You may also have a CPS code since people never hook those back up, break them, or use an S13 transmission with no provision for it.

For the VSS, it's a signal generator. If wired backwards it just won't work, there's no voltage applied to it.