I am currently working on the exhaust manifold on the stated truck. There is a metal tube that screws into the manifold, makes a 90, and runs near the firewall and screws into a male end near the air cleaner. It is "crimped" badly from a previous repair job. Is this the EGR tube? The truck seems to run fine without it, but I guess I should replace it. I called Everything Nissan and they said it sounds like it is the EGR tube ($40!!!). Any info is appreciated. Thanks.