WARNING FOR BUYING CATTED DOWNPIPES!!!
Page 1 of 6 123456 LastLast
Results 1 to 15 of 88

This is a discussion on WARNING FOR BUYING CATTED DOWNPIPES!!! within the Engine Modifications forums, part of the Tech & Modifying & General Repairs category; If you live in an area that does advanced smog testing.. don't waste your money on a catted downpipe. I ...

  1. #1
    UnBanned Sinister's Avatar
    Join Date
    Nov 2006
    Location
    Denver Metro Area
    Posts
    17,627
    I Support ClubWRX

    WARNING FOR BUYING CATTED DOWNPIPES!!!

    If you live in an area that does advanced smog testing.. don't waste your money on a catted downpipe.

    I bought a catted downpipe a few years back, and had to go this month for my emissions testing.

    At Advanced Smog Testing Facilities they test HC (Hydrocarbons) CO2 (Carbon Dioxide) and NOx (Nitrogen Oxide)

    My Catted Downpipe allowed me to pass HC and CO2. But I failed NOx miserably!!

    Here's the important part:
    I spoke with the state emissions inspector (very nice guy btw) and he advised me that on WRXs... we have 2 cats in the downpipe because we don't have an EGR system. The two cats are used to break down the NOx. One cat would be sufficient to break down the HC and CO2 (just as mine was). But only our stock exhaust is able to break down the NOx.

    I asked him how to reduce NOx levels without putting a stock exhaust back on. He said that NOx is produced by high EGTs (exhaust gas temperatures). Our turbo charged cars run a higher EGT than the standard car (1400degrees is common).

    The only ways to decrease NOx are with alcohol/water injection, an alcohol fuel source (E85) or increasing the fuel / retarding the timing.

    Retarding timing / increasing fuel would allow less fuel to be burned increasing the HC output. Alcohol / Water injection would lower the NOx level, but not enough. E85 would also lower the NOx level... but not down to levels acceptable for a 4cyl car.

    Solution? Stock downpipe for emissions testing. And Catless for stage 2+
    Last edited by Sinister; 01-29-2011 at 02:59 PM.
    Kevin
    Moderator
    Sinister's Blowoff Valve FAQ
    WRX Gas Mileage FAQ
    Sinister's Progress Thread - 430whp 429wtq - Sold
    Firearms Enthusiasts Thread

    The Sheriff's Star at the bottom left corner rates a user's reputation.
    If you found a user's post to be helpful or quite the opposite, please make it known to them by clicking the Star!

  2. Remove Advertisements
    ClubWRX.net
    Advertisements
     

  3. #2
    Registered User
    Join Date
    Oct 2010
    Posts
    3
    You will pass on e85. People have passed catless on it.

  4. #3
    UnBanned Sinister's Avatar
    Join Date
    Nov 2006
    Location
    Denver Metro Area
    Posts
    17,627
    I Support ClubWRX
    Quote Originally Posted by Tohsh View Post
    You will pass on e85. People have passed catless on it.

    Sent from my DROIDX using Tapatalk
    passed NOx? and where?
    Kevin
    Moderator
    Sinister's Blowoff Valve FAQ
    WRX Gas Mileage FAQ
    Sinister's Progress Thread - 430whp 429wtq - Sold
    Firearms Enthusiasts Thread

    The Sheriff's Star at the bottom left corner rates a user's reputation.
    If you found a user's post to be helpful or quite the opposite, please make it known to them by clicking the Star!

  5. #4
    Geriatric Ginger Mod Rogan's Avatar
    Join Date
    May 2007
    Location
    behind the wheel
    Posts
    8,188
    I Support ClubWRX
    Quote Originally Posted by Tohsh View Post
    You will pass on e85. People have passed catless on it.

    Sent from my DROIDX using Tapatalk
    I think his point is that cat vs catless: the price difference isn't worthwhile, if you're only doing it to try and pass emissions..


    That's what I got from reading it. Is that correct, Kevin?



    Oh, and welcome to the forum, Tohsh.
    Rogan o_0
    '96 Dodge 2500 CTD @ 40psi - over 700 lb/ft TQ, 7" stack, and 5speed! - SOLD
    '01 Dodge 2500 CTD 6-holed hand-shaker - 3850# dual disk - 900 lb/ft - SOLD
    '97 Dodge 3500 CTD DUALLY built Auto - 40psi boosties - 750 lb/ft

  6. #5
    Registered User
    Join Date
    Oct 2010
    Posts
    3
    California. All I know is we have strict smog regulations but can't recall if they test nox.

  7. #6
    UnBanned Sinister's Avatar
    Join Date
    Nov 2006
    Location
    Denver Metro Area
    Posts
    17,627
    I Support ClubWRX
    Quote Originally Posted by Rogan View Post
    I think his point is that cat vs catless: the price difference isn't worthwhile, if you're only doing it to try and pass emissions..

    That's what I got from reading it. Is that correct, Kevin?
    Exactly what I was going for.
    Kevin
    Moderator
    Sinister's Blowoff Valve FAQ
    WRX Gas Mileage FAQ
    Sinister's Progress Thread - 430whp 429wtq - Sold
    Firearms Enthusiasts Thread

    The Sheriff's Star at the bottom left corner rates a user's reputation.
    If you found a user's post to be helpful or quite the opposite, please make it known to them by clicking the Star!

  8. #7
    UnBanned Sinister's Avatar
    Join Date
    Nov 2006
    Location
    Denver Metro Area
    Posts
    17,627
    I Support ClubWRX
    Quote Originally Posted by Tohsh View Post
    California. All I know is we have strict smog regulations but can't recall if they test nox.
    In california they do test NOx, but they test you at 15 and 25mph.

    In Colorado we have a full dyno test that is variable, and includes acceleration under load on the dyno. They accelerate several times up to 60 mph during this test which takes up to 5 minutes.

    The state inspector advised me that he has had several modified vehicles still fail NOx while tuned for E85.
    Kevin
    Moderator
    Sinister's Blowoff Valve FAQ
    WRX Gas Mileage FAQ
    Sinister's Progress Thread - 430whp 429wtq - Sold
    Firearms Enthusiasts Thread

    The Sheriff's Star at the bottom left corner rates a user's reputation.
    If you found a user's post to be helpful or quite the opposite, please make it known to them by clicking the Star!

  9. #8
    Geriatric Ginger Mod Rogan's Avatar
    Join Date
    May 2007
    Location
    behind the wheel
    Posts
    8,188
    I Support ClubWRX
    http://www.aa1car.com/library/tr1196.htm

    Most vehicles that are in good running condition and properly maintained should pass an emissions test. In some cases, though, minor problems may cause the vehicle to fail an emissions test. These include:

    * Engine and/or converter not at operating temperature. If a vehicle is only driven a short distance to the test facility, it may not be warm enough for the engine to be at normal operating temperature and/or the converter at light-off temperature. This will affect the emissions of the engine and may cause it to fail. Excessive idling while waiting in a test lane may also cause the catalytic converter and/or oxygen sensor to cool down enough where they may not control emissions properly causing higher than normal readings.
    * Idle speed too high. A few hundred rpm can sometimes make the difference between passing and failing an emissions test if emissions are marginal.
    * Dirty air filter. A restricted air filter will choke off the engines air supply, causing higher than normal CO readings.
    * Worn or dirty spark plugs. Excessive plug gap and fouling deposits can create ignition misfire resulting in excessive HC emissions.
    * Dirty oil. The oil in the crankcase can become badly contaminated with gasoline if a vehicle has been subject to a lot of short trip driving, especially during cold weather. These vapors can siphon back through the PCV system and cause elevated CO readings.
    * Pattern failures. Some vehicles tend to be dirtier than others for a given model year because that is the way they were built. It may be the design of the engine, or the calibration of the fuel or engine control system. These kinds of problems may require special "fixes" that can only be found in factory technical service bulletins.

    In areas that have plug-in OBD II emissions testing for 1996 and newer vehicles, the vehicle will be rejected for testing if all of the required OBD II readiness monitors have not run. This may require driving the vehicle for several days until all the monitors have run. The vehicle will also fail the test if (1) the test computer cannot establish communication with the vehicle PCM (defective or disabled diagnostic connector), (2) if the Malfunction Indicator Lamp (MIL) is on, or there are fault codes in the PCM. If the OBD II system is working properly, the MIL is not on and there are no codes, the vehicle should pass the test.

    to pass, you need this combined part: a catted muffler..

    Rogan o_0
    '96 Dodge 2500 CTD @ 40psi - over 700 lb/ft TQ, 7" stack, and 5speed! - SOLD
    '01 Dodge 2500 CTD 6-holed hand-shaker - 3850# dual disk - 900 lb/ft - SOLD
    '97 Dodge 3500 CTD DUALLY built Auto - 40psi boosties - 750 lb/ft

  10. #9
    He simply abides. SD_GR's Avatar
    Join Date
    Jul 2002
    Location
    CA, US
    Posts
    22,478
    I Support ClubWRX
    Quote Originally Posted by Tohsh View Post
    California. All I know is we have strict smog regulations but can't recall if they test nox.
    How would a catless car pass emissions in CA, given the visual test?...
    WRX Info Links, Courtesy TheJ
    The world breaks everyone and afterward many are strong in the broken places. Ernest Hemingway
    I lied. I cheated. I bribed men to cover the crimes of other men. I am an accessory to murder. But the most damning thing of all... I think I can live with it. And if I had to do it all over again - I would. Benjamin Sisko
    DISCLAIMER: Opinions expressed are the author's alone and are inherently worthless.

  11. #10
    Geriatric Ginger Mod Rogan's Avatar
    Join Date
    May 2007
    Location
    behind the wheel
    Posts
    8,188
    I Support ClubWRX
    Quote Originally Posted by SD_GR View Post
    How would a catless car pass emissions in CA, given the visual test?...
    good point.
    Rogan o_0
    '96 Dodge 2500 CTD @ 40psi - over 700 lb/ft TQ, 7" stack, and 5speed! - SOLD
    '01 Dodge 2500 CTD 6-holed hand-shaker - 3850# dual disk - 900 lb/ft - SOLD
    '97 Dodge 3500 CTD DUALLY built Auto - 40psi boosties - 750 lb/ft

  12. #11
    UnBanned Sinister's Avatar
    Join Date
    Nov 2006
    Location
    Denver Metro Area
    Posts
    17,627
    I Support ClubWRX
    Quote Originally Posted by SD_GR View Post
    How would a catless car pass emissions in CA, given the visual test?...
    Great point. Tohsh's point can't be legitimate.
    Kevin
    Moderator
    Sinister's Blowoff Valve FAQ
    WRX Gas Mileage FAQ
    Sinister's Progress Thread - 430whp 429wtq - Sold
    Firearms Enthusiasts Thread

    The Sheriff's Star at the bottom left corner rates a user's reputation.
    If you found a user's post to be helpful or quite the opposite, please make it known to them by clicking the Star!

  13. #12
    UnBanned Sinister's Avatar
    Join Date
    Nov 2006
    Location
    Denver Metro Area
    Posts
    17,627
    I Support ClubWRX
    Thanks to he who stickied.
    Kevin
    Moderator
    Sinister's Blowoff Valve FAQ
    WRX Gas Mileage FAQ
    Sinister's Progress Thread - 430whp 429wtq - Sold
    Firearms Enthusiasts Thread

    The Sheriff's Star at the bottom left corner rates a user's reputation.
    If you found a user's post to be helpful or quite the opposite, please make it known to them by clicking the Star!

  14. #13
    Registered User Pactin's Avatar
    Join Date
    Nov 2007
    Location
    California
    Posts
    755
    Quote Originally Posted by SD_GR View Post
    How would a catless car pass emissions in CA, given the visual test?...
    False/gutted piping. If the tech isn't thorough enough, an empty catalyst chamber or welded heat shield could be enough to fool him.
    --Justin

    Hawk-Eye Alliance #128

  15. #14
    Geriatric Ginger Mod Rogan's Avatar
    Join Date
    May 2007
    Location
    behind the wheel
    Posts
    8,188
    I Support ClubWRX
    Quote Originally Posted by Pactin View Post
    False/gutted piping. If the tech isn't thorough enough, an empty catalyst chamber or welded heat shield could be enough to fool him.
    not trying to be too picky, here, but I think the reference is "buying" a catless up-pipe, not hollowing the stocker.
    But I totally see what you're saying.
    Rogan o_0
    '96 Dodge 2500 CTD @ 40psi - over 700 lb/ft TQ, 7" stack, and 5speed! - SOLD
    '01 Dodge 2500 CTD 6-holed hand-shaker - 3850# dual disk - 900 lb/ft - SOLD
    '97 Dodge 3500 CTD DUALLY built Auto - 40psi boosties - 750 lb/ft

  16. #15
    Registered User jd92677's Avatar
    Join Date
    Jul 2010
    Location
    Cincinnati
    Posts
    2,136
    One thing to think about when going catless, besides the environmental impact, which is obvious, is that it is against federal EPA regulation to knowingly remove the catalytic converters from a vehicle. I believe the fine is up to $50k now for a service center that removes it and $15k for the owner of the vehicle. For me, that's enough to go catted.

Page 1 of 6 123456 LastLast

Posting Permissions

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