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Ditching the 'cat

Discussion in 'The Garage' started by big94gmc, Jan 20, 2007.

  1. big94gmc

    big94gmc 1/2 ton status

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    Just drove back down to P'cola to wrap up a few things.... 'Round abouts Clemson, SC, the '94 started lurching like it was running outta fuel. Obviously, I wasn't, so I was baffled. I turned the stereo down to a whisper, and just listened to the truck....if something was gonna happen, I wanted to be alert. Occassional sputtering continued all through GA, and I was still clueless. I pulled off the interstate in Hogansville, GA to stretch and let the dog go potty, so used the opportunity to put my window down and listen. I could make out a clanking/rattling sound. I parked, got under, and started searching with my ears. My catalytic converter was rattling like a group of black men playing dice in a dark alley.... 172,000 miles on the truck, 172,000 miles on that 'cat - I think it gave me more than could be expected. So, even though my truck's performance was terribly $hitty, I made it down here to my place.

    Here's the question: How will my power/performace react to no 'cat in the pipe, and putting a piece of straight pipe there in it's place?? Would back pressure become an issue? Anything else I need to take into consideration? (Oh, yea....I don't give a $hit about emissions, so, omit that topic from the conversation.)
     
  2. 1977k5

    1977k5 3/4 ton status Vendor

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    You will be fine. If your truck has a heated O2 sensor behind the cat (which it probably does) than you will probably pick up a check engine light telling you that the cat isn't working right.
     
  3. bigblazer87

    bigblazer87 1/2 ton status

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    Just cut your exhaust off after the collector, it'll be fine...
     
  4. big94gmc

    big94gmc 1/2 ton status

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    Yea, I thought about that.... Just cutting two holes in the hood, and running towers straight upward! NOOOOOOOOOOOOOOOOT!!!
     
  5. 4xcrazy

    4xcrazy 3/4 ton status

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    my '94 doesn't have that secondary O2 sensor, so he is probably ok...

    weird you mention the rattling n oise, mine just started doing this a few weeks ago, i pinpointed it to the cat as well, but no power loss with mine :crazy:
    just alot of noise until it heats up real good.
     
  6. sweetk30

    sweetk30 professional hooker Premium Member

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    i felt big power from old tbi 350 when i choped off the old style ball cat. wow.
     
  7. badmix

    badmix 1/2 ton status

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    Well. lemme tell ya a story.

    I have dual exhaust put on my K5 (84 btw) and I had hedman headers and then flowmasters put on, no cats. the truck we raspy and had some bad fumes coming out the tailpipes. I ended up putting two Catco cats on and it quieted the exhaust down alot and no more fumes. I had zero power loss when I put the cats on. So dunno.
     
  8. 4xcrazy

    4xcrazy 3/4 ton status

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    I believe he was referring to those old flat style cats that used the beads in them, i had a few of those and yeah, they didn't flow too well,,,,

    you installed Catco cats,,,those are a more free flowing cat, using the honecomb grid inside i believe, which i also believe most cats are made like now anyways...

    Cats now days have become more efficient and better flowing units than the old styles, notice how much smaller they are than the old ones:laugh: ,,,

    I'd say just replace the cat with a nice aftermarket unit anyways. :D
     
  9. muddybuddy

    muddybuddy 3/4 ton status

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    you dont need the cat. you wont lose any power without it.
     
  10. big94gmc

    big94gmc 1/2 ton status

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    3" pipe will be cheaper than a 'cat.... Money talks, unfortunately.
     

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