96 ls400 engine swap

[jfillis]

I bought a 96 ls400 thinking I was getting a good deal but ended up having to put another engine it. The engine currently in it is not the original. But it is a 1UZ. The one I'm putting in is also a 1UZ. I pulled the old engine but noticed that the wiring harness has a lead to the left O2 censor but not the right. Are both of these engines not the stock engine for the 96 ls? The wiring harnesses are exactly the same and neither seem to have the right O2 sensor lead. At about where the right 02 sensor wires should appear there is a lead that goes to the oil pump. Any help would be appreciated.

 

[pinkytamz]

have you sorted this yet .if not what are the ecu numbers