Thread: What brand CAT is best? Should I go high-flow?

Results 1 to 12 of 12
  1. #1 What brand CAT is best? Should I go high-flow? 
    SE Level Member Blacknight02GT's Avatar
    Join Date
    Feb 2009
    Location
    Buffalo,NY
    Posts
    133
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    So, recently my stock cat converter clogged ( I believe there was an extended service bulletin on 01-02's but mine is well past 10 years old now) and I had to gut it and weld it back on "for now"; but I live in NY and need it fixed ASAP to pass emissions inspection. Is this a good excuse to go the performance route with a bigger downpipe and high flow cat? Or should I go with a stock type replacement? I dont want to have to worry about CEL's and looking for the best fitment, quality build, and easy installation option. Thoughts?
    2002 Grand Prix GT (K&N + Ram Air = BEAST)
    Reply With Quote  
     

  2. #2 Re: What brand CAT is best? Should I go high-flow? 
    Awesome Level Member chrsmi1's Avatar
    Join Date
    Jan 2013
    Location
    Raleigh, NC
    Posts
    824
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    http://www.amazon.com/Magnaflow-5995...ytic+converter

    And if you can afford the extra $200, buy some speed daddy headers. They Go great together.
    Comp G. E85, 2.8, Headers, Tune, Intake, S1X, 105# springs, 60 # injectors, 255 walbro,etc.

    *NEW* 2002 Camaro Z28- Lid, Headers, Catback

    Reply With Quote  
     

  3. #3 Re: What brand CAT is best? Should I go high-flow? 
    Killa Bee Scottydoggs's Avatar
    Join Date
    Aug 2010
    Location
    new jersey
    Posts
    39,927
    Thanks (Received)
    63
    Likes (Received)
    166
    Dislikes (Received)
    5
    ny is carb compliant now from what i hear. aka same dumb rules as CA.

    98 Buick Regal GS, F body brakes, Caddy STS wheels, tinted tails L36 bottom end, lightly ported heads, 1.95 roller rockers, headers, gen 5 N* 3.0 pulley, FSIC, 42 lb injectors, a BrandonHall rebuilt trans, DHP tuned and AEM water/Meth injection https://goo.gl/gpV5kW
    Reply With Quote  
     

  4. #4 Re: What brand CAT is best? Should I go high-flow? 
    Awesome Level Member chrsmi1's Avatar
    Join Date
    Jan 2013
    Location
    Raleigh, NC
    Posts
    824
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Quote Originally Posted by ScottyDoggs View Post
    ny is carb compliant now from what i hear. aka same dumb rules as CA.

    boooooooooooo!

    Move out of NY OP!
    Comp G. E85, 2.8, Headers, Tune, Intake, S1X, 105# springs, 60 # injectors, 255 walbro,etc.

    *NEW* 2002 Camaro Z28- Lid, Headers, Catback

    Reply With Quote  
     

  5. #5 Re: What brand CAT is best? Should I go high-flow? 
    Killa Bee Scottydoggs's Avatar
    Join Date
    Aug 2010
    Location
    new jersey
    Posts
    39,927
    Thanks (Received)
    63
    Likes (Received)
    166
    Dislikes (Received)
    5
    i got a cat like this on my speed daddy headers. http://www.ebay.com/itm/3-Thunderbol...item20d0c877ba

    but i also have my cat and rear o2 deleted in the pcm.

    98 Buick Regal GS, F body brakes, Caddy STS wheels, tinted tails L36 bottom end, lightly ported heads, 1.95 roller rockers, headers, gen 5 N* 3.0 pulley, FSIC, 42 lb injectors, a BrandonHall rebuilt trans, DHP tuned and AEM water/Meth injection https://goo.gl/gpV5kW
    Reply With Quote  
     

  6. #6 Re: What brand CAT is best? Should I go high-flow? 
    GrandPrix Junkie idrivejunk's Avatar
    Join Date
    Jan 2014
    Location
    AR
    Posts
    4,913
    Thanks (Received)
    4
    Likes (Received)
    32
    Dislikes (Received)
    1
    For a fast and sure fit with no hassle, I'd get a salvage downpipe assembly if available. And new gaskets. Be prepared for broken bolts at the cat-back flange (have drill and extra bolt / nut handy). Go soak the flanges in penetrating oil now and give yourself a sporting chance of not breaking!
    All Grand Prix, all the time. 69 Model J, 99 GT & GTP coupes. All junk, haha.
    Reply With Quote  
     

  7. #7 Re: What brand CAT is best? Should I go high-flow? 
    GT Level Member
    Join Date
    Sep 2014
    Location
    Worcester, MA
    Posts
    282
    Thanks (Received)
    1
    Likes (Received)
    1
    Dislikes (Received)
    0
    FYI a catalytic converter heats up to do its job, and depends on a certain amount of exhaust flow to get hot enough to react.

    If you use an oversize catalytic converter, it may never get hot enough and won't control emissions and could eventually clog because it's not "burning" off the residual HC's. A converter that's too small could also get too hot, but I don't know anyone who is going to try to put an undersized converter.

    Be prudent in selection of any non-OEM catalytic converter if you have to pass emissions (and can't just disable the rear O2).
    Reply With Quote  
     

  8. #8 Re: What brand CAT is best? Should I go high-flow? 
    SE Level Member Blacknight02GT's Avatar
    Join Date
    Feb 2009
    Location
    Buffalo,NY
    Posts
    133
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Anyone ever use this Eastern Catalytic converter?
    http://www.rockauto.com/catalog/more...nid=428&jpid=2

    Seems to be one of the closest to stock I can find for aftermarket. Ideally, I'd like to get the set up with the best performance; but also have it not throw a code. I realize this is a fine line and it seems high-flow is impossible to guarantee. Another question: will most of these aftermarket products such as the eastern listed above eliminated the stock "U bend"? It's hard to tell from the photos; but I'm also no exahust expert so i'm not 100% on what I'm looking at.












    5 If so, would this improve performance simply by removing that constriction?
    2002 Grand Prix GT (K&N + Ram Air = BEAST)
    Reply With Quote  
     

  9. #9 Re: What brand CAT is best? Should I go high-flow? 
    SE Level Member Blacknight02GT's Avatar
    Join Date
    Feb 2009
    Location
    Buffalo,NY
    Posts
    133
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Quote Originally Posted by idrivejunk View Post
    For a fast and sure fit with no hassle, I'd get a salvage downpipe assembly if available. And new gaskets. Be prepared for broken bolts at the cat-back flange (have drill and extra bolt / nut handy). Go soak the flanges in penetrating oil now and give yourself a sporting chance of not breaking!
    I'm already planning on putting new bolts and nuts on that; mine is pretty rotted away...
    2002 Grand Prix GT (K&N + Ram Air = BEAST)
    Reply With Quote  
     

  10. #10 Re: What brand CAT is best? Should I go high-flow? 
    SE Level Member Blacknight02GT's Avatar
    Join Date
    Feb 2009
    Location
    Buffalo,NY
    Posts
    133
    Thanks (Received)
    0
    Likes (Received)
    0
    Dislikes (Received)
    0
    Do you guys recommend replacing the O2 sensors too when replacing a cat? nothing appears to be wrong with mine; but they are almost 14 years old
    2002 Grand Prix GT (K&N + Ram Air = BEAST)
    Reply With Quote  
     

  11. #11 Re: What brand CAT is best? Should I go high-flow? 
    GrandPrix Junkie idrivejunk's Avatar
    Join Date
    Jan 2014
    Location
    AR
    Posts
    4,913
    Thanks (Received)
    4
    Likes (Received)
    32
    Dislikes (Received)
    1
    I'd swap it over. Only the rear one is on the DP.
    All Grand Prix, all the time. 69 Model J, 99 GT & GTP coupes. All junk, haha.
    Reply With Quote  
     

  12. #12 Re: What brand CAT is best? Should I go high-flow? 
    Donating Users EHB's Avatar
    Join Date
    Dec 2014
    Location
    Maryland
    Posts
    843
    Thanks (Received)
    0
    Likes (Received)
    1
    Dislikes (Received)
    0
    you should replace them both. a bad O2 sensor doesn't always tell you it's bad by throwing a code. they can be the cause of lost fuel mileage. only buy acdelco sensors. amazon is as cheap as anywhere to get them.
    2000 GTP - 3" Catted DP...ZZP Plog...9" Cone filter...Reptile pcm...3.4 pulley...AL104's
    Reply With Quote  
     

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