Also let me say I am very impressed by your knowledge on the 3.4's. You may be hearing from me soon, good sir!

 

Ok so I took off the EGR valve and started the car. It didn't try to die but it was stumbling around a bit. No black stuff came from the EGR hole either. Also I just noticed this noise. Any ideas??? It's the rattle when the car gets almost back down to idle. Listen carefully and you'll hear it. Sounds like metal on metal. Maybe a heat shield?

What is this rattling noise ??? - YouTube

 

Oh and I could definitely hear exhaust coming from te EGR port. It was stupid loud compared to the EGR being installed. So it's not clogged.

 

Is your exhaust hanging a bit low? If I remember right near where the cat is there's sort of a brace that keeps the exhaust from falling. If it's too low, it makes this noise.

 

I don't think It's hanging low lol

 

It doesn't have to be by much. I doubt it's high enough to hit the heat shield. Did you get under and look at it?

 

Sounds like the bracket for the heat shield that's on top of the cat may be broken loose and rattling.

 

Oh buddy check this out. I replaced my fuel filter like 6 months ago and would have never thought it was clogged. I just took it off and guess what? I dumped the fuel out of it and it was black and mucky. Hopefully an easy fix fixes my problem! On my way to oreillys to get a new filter! Wish me luck!!!

 

Was the inside of your tank clean 6 months ago? Shouldn't be black and mucky now if it was clean.
Hopefully somebody didn't prank you and dump something into your tank.

 

get that in a diesel tank when the fuel bugs die. so you took the fuel filter out and not the pump or replaced the fuel pump and filter 6 mo ago and just took the filter out