Does it seem like it's running rich? Sooty, black tailpipe, etc.

 

No soot but I haven't stuck my fingers in the pipe. It does seem to be running rich I can smell gas when I shouldn't.

 

OK I've run my finger around the tail pipe and it is definitely sooty. Now what?

 

I looked up soot in exhaust and found that it could be the air cleaner, O2 sensor, The IAC, the Computer and a couple of other things. I had to removed the TB to get at the IAC and when I did I found there is oil on the plenum! So either I screwed up or something else went very wrong since I installed the Hughes Engines plenum kit. I ran it and poured some distilled water in the TB to try to cause the oil to vaporize and get burnt. It seems to run like it did before the EGR code set the chk egn light. I expect I will have to redo the plenum with new gaskets. What I recall is that the ones Hughes sent were silicone and the two pieces near the firewall were the most difficult to get to stay in place as I tried to set the intake back on. I expect that is where the leak is. I'm thinkig the plenum oil caused the soot and the EGR code.

 

It just occurred to me that even if the rear gasket moved it wouldn't affect the plenum gasket. That would just send oil down the back of the motor. So I have no idea why it might have failed. I used new plenum bolts and torqued them according to the pattern supplied. I sent Hughes an email informing them and asking for advice. It was 2 years ago this past July when I installed the plenum kit. Is there an M1 style intake for the 3.9?

 

I got a reply from Hughes Engines this morning. Does anyone have any idea where oil might come from if it is not the plenum gasket?
I just thought the PCV valve might be it but its less than 2 years old.

The reply from Hughes;
"I don’t know the answer to your question. Maybe the oil is coming from somewhere else, keep looking."

EDIT- I have started a new thread specific to the oil in the plenum after the plenum kit install.