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  1. #1

    Default catalytic converter

    hey guys, i might sound like an idiot here, but im thinking bout swapping out my exhaust for a custom one, and i was wondering, when you do true duals does that mean the catalytic converter is gone too? do i even need a catalytic converter on my truck? (a 2009 silverado crew cab)
    thanks.
    2009 Chevy Silverado LT

    Performance Mods:
    Flowmaster Cat Back Dual Rear Exhaust
    K&N 63 Series Cold Air Intake
    Pirelli Scorpion ATR All Terrain tires.

    External Mods:
    8000K H.I.D Headlights
    Weston Side Step Bars
    Blacked Out Bowties
    Smoked Out Tail Lights
    6" Euro Style Rubber Antenna

    Internal Mods:
    Pioneer P4200DVD Head Unit
    Pioneer 350 Watt Door Speakers
    Power Acoustic 1250 Watt 2 Way Amplifier
    Two 10" Kicker Comp Subwoofers
    Pioneer Tweeters

  2. #2

    Default

    True duals does not eliminate the cats. I would suggest putting in high flow cats if you are doing a custom true dual set up. that's how i did it on my '02. If you are worried about any kind of emission laws then the cats are a must. If you delete the cats you will need to have the take care of the O2 sensor signal so the CEL doesn't stay on. and with no reading from the O2 sensor the computer can not adjust to keep the truck running at its best.
    2002 Chevy 1500 Ex-cab Z71: 5.3L, auto 4, shorties, hi-flow cats, true dual 2.5" straight pipes, AirAid intake, TBS, Platinum plugs, 8.5mm wires, programmer, 3in w/ 33s, also has the composite bed

    2010 GMC 1500 Crew Cab Z71 w/ All Terrain package: 5.3L, auto 6, 2" Zone leveling kit, AirAid Jr. Intake Kit

  3. #3
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    stephan's Avatar
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    Far West, Oregon USA,
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    Default

    Yep X2 on KWGs advice. We have no way of knowing what the smog laws are where you live & in the majority of gov jurisdictions it's illegal for you to remove the cat(s) on your vehicle
    1988 Chevy C-3500 2wd (no pic)
    350 c.i. 5.7 L Stock Block, 4 Bolt Mains
    L-31 Vortec Heads, Edelbrock Cam & Intake,
    Holley 650, Flowtech Headers, Magnaflow exh.
    Jet Trans 700R4, B&M Ratchet, 4:10 gears,
    3" susp. lift kit "shadetree"
    No rev limiter, No speed limiter lol


  4. #4

    Default

    ok guys thanks!and also, i heard that the shorter the pipes are on the exhaust from the muffler the louder it sounds, is that true?
    2009 Chevy Silverado LT

    Performance Mods:
    Flowmaster Cat Back Dual Rear Exhaust
    K&N 63 Series Cold Air Intake
    Pirelli Scorpion ATR All Terrain tires.

    External Mods:
    8000K H.I.D Headlights
    Weston Side Step Bars
    Blacked Out Bowties
    Smoked Out Tail Lights
    6" Euro Style Rubber Antenna

    Internal Mods:
    Pioneer P4200DVD Head Unit
    Pioneer 350 Watt Door Speakers
    Power Acoustic 1250 Watt 2 Way Amplifier
    Two 10" Kicker Comp Subwoofers
    Pioneer Tweeters

  5. #5
    Legend
    stephan's Avatar
    Join Date
    Sep 2010
    Location
    Far West, Oregon USA,
    Posts
    8,606
    Blog Entries
    1

    Default

    Yep, that's true. It also depends a lot on which muffler(s) you choose or if you leave it off completely. If you think you can skate in your area without getting excessive noise tickets, & you want it loud, take the muffler(s) off & just run it with the cats.
    1988 Chevy C-3500 2wd (no pic)
    350 c.i. 5.7 L Stock Block, 4 Bolt Mains
    L-31 Vortec Heads, Edelbrock Cam & Intake,
    Holley 650, Flowtech Headers, Magnaflow exh.
    Jet Trans 700R4, B&M Ratchet, 4:10 gears,
    3" susp. lift kit "shadetree"
    No rev limiter, No speed limiter lol


  6. #6

    Default

    Quote Originally Posted by stephan View Post
    Yep, that's true. It also depends a lot on which muffler(s) you choose or if you leave it off completely. If you think you can skate in your area without getting excessive noise tickets, & you want it loud, take the muffler(s) off & just run it with the cats.
    thanks alot!
    2009 Chevy Silverado LT

    Performance Mods:
    Flowmaster Cat Back Dual Rear Exhaust
    K&N 63 Series Cold Air Intake
    Pirelli Scorpion ATR All Terrain tires.

    External Mods:
    8000K H.I.D Headlights
    Weston Side Step Bars
    Blacked Out Bowties
    Smoked Out Tail Lights
    6" Euro Style Rubber Antenna

    Internal Mods:
    Pioneer P4200DVD Head Unit
    Pioneer 350 Watt Door Speakers
    Power Acoustic 1250 Watt 2 Way Amplifier
    Two 10" Kicker Comp Subwoofers
    Pioneer Tweeters

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