There are four sensors under the plenum

[BlueMeanies]

What are they? There seems to be an oil leak coming from the one that is between the 6 & 8 cyls. Is that posible?

Can't find any leak at the valve cover or head gasket.

I've looked through the Haynes manual for nada. Thinking of using it for archery practice...

 

[RonJon '06]

Those are your MDS solenoids and if they are leaking oil into your intake then that could be what fouled your cat on the passenger's side.

 

[BlueMeanies]

Ah! Thanks!

 

[hemidup]

Oil from a leaking MDS solenoid will just sit in the cam valley of the block. No way for it to get into your intake.

 

[BlueMeanies]

Thats where it was. There was enough for it to start dripping down to the bottom of the engine.

Hate oil drips on the driveway...