I just bought a 97 c2500 Suburban with 7.4l. PO removed upper intake to replace fuel regulator and twisted the EGR tube closed while trying to disconnect it. He's been running the truck that way for a couple of years. He just unplugged the pigtail on the EGR valve. Truck seems to be running fine. This truck wont be a daily driver but I do plan on towing with it. What harm is being done to engine/exhaust components leaving it like this? Second question: I see replacement tubes on Ebay running anywhere from $35 - $80 for a new one vs. $200+ for a stock used one. Anybody have info on these new replacement tubes?