Even though I didn't make any changes it's leaking vacuum again (was leaking from a oil catch can before) and the car is running really bad and both wideband sensors throw a code for a lean condition. Idle drops every now and then also which didn't happend when it was not leaking. I'm thinking I should go get the upper and lower plenum gasket surface decked at a machine shop.

I think the FSM has some diagram of a smoke machine being used so does anyone know where I can find a smoke machine? I looked and didn't find anything but fog machines.

 

Get a can of carburetor cleaner and with the engine idling, start spraying your vacuum lines. When your RPM changes (which ever line you are spraying when the RPM changes) you have found your leak.

Send $50 paypal to xxhotelcrazyxx@yahoo.com

 

I just bought some of that. I sprayed water earlier yesterday but nothing happened.

 

$5 smoke machine:

Find a friend that smokes, buy them a pack and get to it.

 

The PCV valve seemed to be leaking. Did not changed idle when I sprayed it with brake cleaner. I tried bypassing the oil catch can and it still leaked. I kinked the hose from the PCV valve and the idle was steady and not dropping.

Right now the PCV valve is not drawing any vacuum and it's routed to the catch can. I capped off the upper plenum vacuum port. Only way I could fix it. I might cause the car to smoke a lot at WOT, not sure.
EDIT. nevermind that didn't happen and power is back up.

 

UPDATE
It turns out the PCV valve was faulty so I installed the PCV valve from the original valve cover that came with the car and I have it drawing vacuum again as before and doesn't leak. I changed the original covers months ago and kept them when I tried the Pathfinder aluminum valve covers.

 

UPDATE
That only worked for like 2 hours and it was leaking again. Right now the valve is venting to the catch can without vacuum and it's the only way to keep it from leaking vacuum. I'll drill out the PCV valve to keep crank case pressure to a minimum since it doesn't draw vacuum like it should.


EDIT:
I talked to Kenny@K&D Auto and we both came to the conclusion it's a valve cover leak and I did put on used valve covers from a member here who said they had only 25k miles which was probably a lie. At this point I drilled the PCV valve and the car runs fine but still some power is missing. I'll replace the covers with new ones later before my birthday when registration is due.