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Thread: True duals

  1. #1
    Jr. Engineer
    Z71_usmc_rebel's Avatar
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    Beavercreek,OH (currently stationed in Jacksonville,NC)
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    Default True duals

    If i was to go to my local muffler shop and have them remove all the piping from the headers back then re pipe my exhaust to be true duals with just flow master mufflers and no cats...would that mess with my O2 sensor readings? my state doesnt have emmisions checks so i dont have to worry about that...
    Justin - Beavercreek,OH

    02 Z71 Ext. Cab (fully Loaded)
    * 9" Total Lift (RoughCountry)
    * 35' BF Goodrich Mud Terrain KM2s w/ 16" Chrome Pro Comp wheels
    * Hypertech Maxx Energy Programmer
    * K&N Intake
    * BlackOut Tails

  2. #2


    Yes, I think. I guess they still have two on each side for calculating fuel / air mixtures for the computer.

    2010 Z/71 Colorado C/C
    Black 4X4 w/5.3L V8
    2007 Winnebago Adventurer
    w/8.1L Chevy & Allison 6spd.
    Canyon Lake, Texas

  3. #3


    Yeah, you need the cats and O2 sensors there, otherwise it'll throw a code, and can negatively effect performance as well.

    The cats already flow pretty darn well on these trucks. And what little restriction they do have is actually beneficial as it provides some much needed low-end torque. Our trucks aren't exactly light! Just go with a cat-back system. You can get that to sound pretty darn loud if you want it to.

    2009 GMC Sierra Denali AWD

  4. #4


    If you really want to run without the cats, then a quick and easy way to avoid throwing a code is to put the second O2 sensor on a spark plug extension and then plug the spark plug extension into the piping. I picked one up at Checkers for less than $5. Just make sure you get one with the right threads.

    I did this on my race/street car that I had a standalone ECU in, with a wideband O2 sensor, so I'm not sure what doing this to a vehicle without those things will do to your air/fuel mixture.

  5. #5


    It will sound mean as hell!

    08' Silverado Ext. Cab
    Texas Edition
    Flowmaster 40 series duals
    Windows tinted 5% all around
    Remote start
    Garmin nuvi 260 GPS
    K & N Air Flow
    Sirius Stilletto 2 Radio

  6. #6


    You can buy O2 simulators that plug in where the O2's did and the compmuter won't know they are missing. The simulator sends the computer what a normal working O2 sensor would send on stock running vehicle.

    99 K 1500 Suburban
    78 Silverado Big 10 w/factory 454
    00 S-10 Blazer
    1976 Trans Am
    1980 Honda CB900 Custom

  7. #7
    Jr. Engineer
    Z71_usmc_rebel's Avatar
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    hmm i didnt know that... im gonna go with the cat back...i dont need to lose performance or gas mileage..but i was just wandering what it would if i did only straight pipes back! thanks guys

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