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Catalytic converter emptied, do I need pipe?

Discussion in 'Performance & Tuning' started by Harleymick, Nov 13, 2019.

  1. Nov 13, 2019 at 7:25 PM
    #1
    Harleymick

    Harleymick [OP] Well-Known Member

    Joined:
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    First Name:
    Mick
    Vehicle:
    1999 Jeep Wrangler Sahara
    6 inch lift, 35" tires, .488 gears and 4.7L Stroker pushing 300 HP
    To go along with the improved exhaust flow of a new header I took the cat off and totally hollowed it out. As long as both O2 sensors are connected the reprogrammed ECM doesn't care and I do not get an error code. Just wondering if the empty space in the cat creates a restriction at higher speeds. Should I run a piece of exhaust pipe through it to keep the exhaust in a straight shot?
     
  2. Nov 13, 2019 at 8:12 PM
    #2
    aggrex

    aggrex Well-Known Member

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    Tuffy>AEV>TTO>JW>STech>EVOcage>MagnaFlow>SpiderTrax>RockHard>TF>SpringTail>67design>Bolt>GPCA>Curt>
    IMO straight pipe would flow better but if there are no error codes I would leave it alone for the speeds your TJ will be running.
     
  3. Nov 13, 2019 at 8:33 PM
    #3
    Harleymick

    Harleymick [OP] Well-Known Member

    Joined:
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    Member:
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    Messages:
    76
    Gender:
    Male
    First Name:
    Mick
    Vehicle:
    1999 Jeep Wrangler Sahara
    6 inch lift, 35" tires, .488 gears and 4.7L Stroker pushing 300 HP
    Thanks, but what speeds did you mean? If I drive to Charlotte I have to go 80 at least part of the way. It's very stable at least up to 90 with the current suspension setup.
     
  4. Nov 13, 2019 at 9:06 PM
    #4
    aggrex

    aggrex Well-Known Member

    Joined:
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    Messages:
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    Vehicle:
    Backcountry '16
    Tuffy>AEV>TTO>JW>STech>EVOcage>MagnaFlow>SpiderTrax>RockHard>TF>SpringTail>67design>Bolt>GPCA>Curt>
    The empty space could possibly have some minor restriction but probably no more than a resonator or functioning high flow cat. Forgot you're running that 300HP stroker LOL. Comparison test on speed and mpg with a straight pipe vs empty cat. Post up the data as it would be interesting.
     
  5. Nov 27, 2019 at 10:21 PM
    #5
    Harleymick

    Harleymick [OP] Well-Known Member

    Joined:
    Nov 27, 2018
    Member:
    #2742
    Messages:
    76
    Gender:
    Male
    First Name:
    Mick
    Vehicle:
    1999 Jeep Wrangler Sahara
    6 inch lift, 35" tires, .488 gears and 4.7L Stroker pushing 300 HP
    To the owner of Golen engines who built the engine and he advised me that with the rest of the exhaust being straight through the turbulence caused might make a small difference above 3,000 rpm but it was totally my choice. I can't afford to spend hundreds on more dyno tests out of curiosity. The first one was enough.
    77365899_205311840481041_221660144429799_6a4d3949f0964ec5e0a39fc1824e2071e42f3093.jpg
     
    aggrex likes this.
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