Results 1 to 10 of 10

ORY vs. Y with Cats

This is a discussion on ORY vs. Y with Cats within the External Engine forums, part of the LSx Technical Help Section category; Costs aside, is there any difference in longevity, power, ability to pass inspections in Texas (very important!!), tuneability, , ground ...

  1. #1
    Senior Member Tobynine9's Avatar
    Join Date
    Nov 2005
    Location
    Cypress, Texas
    Age
    36
    Posts
    1,054

    Burple
    1966 427 Cobra Replica

    ORY vs. Y with Cats

    Costs aside, is there any difference in longevity, power, ability to pass inspections in Texas (very important!!), tuneability, , ground clearance, etc. between a long tube header set up with a catted y-pipe (considering the Kooks package) and a long tube header set up with an off road y-pipe and O2 sensor simulators (considering the Hooker package).

    I really know nothing about all this so I apologize if it's a foolish question. I've searched through the forums and haven't found any threads that directly address this issue.

    Remember, this is irregardless of costs (I know the Hookers/Flowtechs/Hedmans/Pacesetters are cheaper). If I have to spend more $ to be legal I will. Thanks.

  2. #2
    Senior Member Tobynine9's Avatar
    Join Date
    Nov 2005
    Location
    Cypress, Texas
    Age
    36
    Posts
    1,054

    Burple
    1966 427 Cobra Replica

    Bueller...? Bueller...?

  3. #3
    We'll be back... GatorSS's Avatar
    Join Date
    Aug 2005
    Location
    THE SWAMP
    Posts
    1,446

    Light Pewter Metallic
    2000 Camaro SS M6

    The short answer to that three-parter is:
    1) Longevity will be much longer without catz, 'cause they'd be the first thing to go.
    2) Power would be slightly higher with the ORY, due to less restriction (better flow).
    3) I don't know about Texas inspections, but if they require a visual inspection or an actual "sniff" test, you'll need the cats to pass. Otherwise, you'll pass with ORY and the O2 sims.
    Last edited by GatorSS; 11-24-2005 at 07:19 PM.

  4. #4
    ruff ruff rotwiler's Avatar
    Join Date
    Aug 2005
    Location
    WA State
    Age
    51
    Posts
    481

    LT's, 3400 stall, FIPK,CB
    2002 Z28

    You need 02 sims for the back 02's or need them deleted from your pcm on any headers you get cats or offroad Y or you will get a check engine light. Gain from tons of people who have dyno'd both is around 5h.p average with no cats. Ground clearance is dependant on the header design and setup. I have removable cats and the flange the cat or pipe bolts to is what scrapes on really steep driveways that level out flat. Otherwise I have zero problems. I do suggest anyone with LT's get a tune, my car was at a really rich 10.9:1 with just the LT's and seen 11 h.p gain, with a quick change of WOT A/f on the dyno using the Predator tuner I gained 24(in area, might be slightly more) when I brought my A/F to 12.9:1.

  5. #5
    Senior Member Tobynine9's Avatar
    Join Date
    Nov 2005
    Location
    Cypress, Texas
    Age
    36
    Posts
    1,054

    Burple
    1966 427 Cobra Replica

    Yeah, I should have thought of this earlier. My brother is certified to do emissions inspections in TX. He said he has to do a visual inspection and that I have to have some sort of cats on the system. Whether or not they've been cored out and aren't functioning is a different story.

    If I were to run an ORY, is there any issue with the computer messing up the a/f mixture because it's not getting a real reading from what would be the rear O2 sensor?

  6. #6
    Senior Member Tobynine9's Avatar
    Join Date
    Nov 2005
    Location
    Cypress, Texas
    Age
    36
    Posts
    1,054

    Burple
    1966 427 Cobra Replica

    BTW, thanks for the input y'all.

  7. #7
    We'll be back... GatorSS's Avatar
    Join Date
    Aug 2005
    Location
    THE SWAMP
    Posts
    1,446

    Light Pewter Metallic
    2000 Camaro SS M6

    Quote Originally Posted by Tobynine9
    Yeah, I should have thought of this earlier. My brother is certified to do emissions inspections in TX. He said he has to do a visual inspection and that I have to have some sort of cats on the system. Whether or not they've been cored out and aren't functioning is a different story.

    If I were to run an ORY, is there any issue with the computer messing up the a/f mixture because it's not getting a real reading from what would be the rear O2 sensor?
    Only the front 02 sensors affect a/f mixture. The rear 02 sensors only monitor the effectiveness of the cats and their only consequence is to throw a code and turn on your SES light. 02 simulators will prevent the code and SES light. If you use tuning software, you can just delete the function of the rear sensors from the VCM.

  8. #8
    ruff ruff rotwiler's Avatar
    Join Date
    Aug 2005
    Location
    WA State
    Age
    51
    Posts
    481

    LT's, 3400 stall, FIPK,CB
    2002 Z28

    If you change back and forth from no cats to cats it does throw your pcm off some because you flow a little better. Should just richen it up the A/F without cats. I like the cats on and sounds much better with them.

  9. #9
    We'll be back... GatorSS's Avatar
    Join Date
    Aug 2005
    Location
    THE SWAMP
    Posts
    1,446

    Light Pewter Metallic
    2000 Camaro SS M6

    I wouldn't change back and forth, I'd stick with one setup, either with or without cats. Nevertheless, such changing shouldn't be hard for the VCM to adjust since the flow difference is small.

  10. #10
    ruff ruff rotwiler's Avatar
    Join Date
    Aug 2005
    Location
    WA State
    Age
    51
    Posts
    481

    LT's, 3400 stall, FIPK,CB
    2002 Z28

    I switched to no cats after I had the car tuned for cats and I set my bests with the cats on, so I was losing some power with the cats off and it not tuned for it. I did et drags every week this summer and going out 30 times and running simular times and the first time out with cats I ran a new best and ran better the rest of the season. I have seen some say they had good gains without a tune, but wasn't that way for me. Even a little thing like a billet breather threw my fuel trims off and my car was seeing unmetered air. Monitored my Fuel trims after the LT headers and could tell when a header bolt was loosened enough to suck air because I'd see my fuel trims go +, tighten the bolt and right back to slightly -, the breather did the same thing and sent me slightly +. Maybe my car is sensitive to changes, but I do get better gas mileage when the Fuel trims are right on and can tell a difference. Even just going from Cats to no cats I would get a odd backfire at times.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Cats VS No Cats for a catback exhaust system
    By Guerrillakilla13 in forum Firebird / WS6
    Replies: 23
    Last Post: 04-25-2011, 11:33 AM
  2. CATS!!! Cats on my Paint :(
    By Intrepidman in forum Almost Anything Goes
    Replies: 41
    Last Post: 03-28-2009, 08:29 AM
  3. How do I gut my cats out ?
    By Speedy_Gonzales in forum External Engine
    Replies: 13
    Last Post: 08-03-2008, 02:24 PM
  4. Cats? No Cats? High Flow Cats??
    By lx24 in forum Firebird / WS6
    Replies: 2
    Last Post: 08-17-2007, 09:11 PM
  5. cats
    By camarostripes96 in forum External Engine
    Replies: 11
    Last Post: 10-02-2006, 04:37 PM

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
  •