Results 1 to 3 of 3

Thread: 2020 Exhaust System

  1. #1
    Join Date
    Dec 2004

    Default 2020 Exhaust System

    New 2020 GMC Truck purchased and while checking out the massive exhaust I noticed the extension on the end of the pipe giving the impression of a much larger exhaust. To my surprise the end of the pipe necks down to a 2 3/4" opening. That has me worried, on my old truck I had an exhaust temperature gauge so I could monitor the heat on a long pull. The new truck has no exhaust temperature readout anywhere I can find. It's the LP5 Duramax rated pretty high in torque and hp. Is 2 3/4" enough opening to get all the exhaust gases out without overheating the turbo? Can the opening be increased without setting any codes?
    02 2500HD LT D/A SB CC 4X4 BLACK, Westin stainless nerf bars, BW GN Hitch,Racor 60S post oem fuel filter, Oil Guard bypass engine oil Filter. All synthetic fluids. Kennedy boost valve, edge, Modified air intake,EGT & Boost digital gauge,TransferFlow combo fuel & tool box, Air Lift Suspesion Bags Rear & compressor with remote, Bilsteins front & rear, Frontier front replacement bumper.

  2. #2
    Join Date
    Apr 2001


    A larger exit may be beneficial in some ways, but would certainly compromise the designed DPF regeneration process. The tailpipe is designed to cool the exiting gases to some measured degree so we don't set pedestrians on fire (hard-learned Ford lesson). Any modification or aftermarket solution must take this into consideration, as well.

    As far as the size vs. power vs. heat goes, they aren't blowing up while making ridiculous gobs of power, so it may be a solution in search of a problem.
    1985 Blazer 6.2
    2001 GMC 2500HD D/A

  3. #3
    Join Date
    May 2021
    Palatka Florida


    I have been wondering the same thing about the smaller exhaust pipe. We don’t want speed just towing capacity and durability. We hope that this is the last vehicle that we buy. We’re close to both of us being retired.

Similar Threads

  1. exhaust system upgrades
    By eddie mcdow in forum Duramax 6600
    Replies: 1
    Last Post: 01-24-2012, 17:37
  2. exhaust system
    By allformike in forum 6.2L Diesel - Tech Support - Troubleshooting - Performance
    Replies: 1
    Last Post: 01-05-2008, 20:17
  3. Can I build my own exhaust system?
    By Shaun091382 in forum 6.5L Turbo Diesel - Tech Support - Troubleshooting - Performance
    Replies: 16
    Last Post: 09-09-2003, 07:19
  4. No Cat exhaust system '93 6.5TD
    By Shaun091382 in forum 6.5L Turbo Diesel - Tech Support - Troubleshooting - Performance
    Replies: 0
    Last Post: 08-29-2003, 11:40
  5. Duramax OEM Exhaust System
    By RVGuy in forum Duramax 6600
    Replies: 4
    Last Post: 08-19-2002, 09:12

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts