1986 300zx Turbo rough idle, exhaust leak

I am new here, and I hope I am doing this right. I just got a 1986 300zx Turbo. This car is pristine, however I have an exhaust leak (passenger side) that sounds like it is behind timing cover. Exhaust manifold bolts are tight, no cracks, and it is running rough. I am trying to locate a diagram of the exhaust system for turbo models but can not find one. :banghead: If any one here has some suggestions I would be very grateful. I am the 2nd owner, it has 145,000 miles on it. Replaced plugs, wires, o2 sensor, cap, fuel filter. Please help, thanks.

Shoot me a PM and I'll hook you up. Think I still have a FSM for the Z31 around here somewhere.

You could probably use a smoke test to pin point an exhaust leak.

Any leaks up-stream of the O2 sensor will give a false signal to the ECU/PCU which will formulate a bad air/fuel mix.

I wonder if the Turbo is working!
Also do a catalytic converter back pressure test.