P0420 & P0430: Stock replace or magnaflow? Advice please

Discussion in 'N/A Mods & Tuning' started by lvxr, Jun 27, 2015.

  1. lvxr

    lvxr Member

    Joined:
    Feb 12, 2008
    Messages:
    934
    Likes Received:
    0
    P0420 & P0430: Replace stock cats or go magnaflow? Advice please

    Hey guys, long time member here but I've basically been a ghost over the last few years. My cats finally took a shit on me and i need advice on what I should do.

    I can't pass smog and I need to replace my cats. Here's where I need your guys' help:

    Buy stock replacements, or buy magnaflow cats. Or chime in if you have an alternate option.

    Also, am i just changing the 2 cats (right & left) on the header, or do i need to change all 4?



    I replaced both AFR's and both O2's less than a year ago (OEM, not cheapo's) so don't worry about that. Performance-wise, my truck is bone stock.

    Thank you in advance, im open to all opinions and advice. :top:
     
    #1 lvxr, Jun 27, 2015
    Last edited: Jun 27, 2015
  2. Gators Taco

    Gators Taco <a . href="http://www.xr-underground.com/forum/sho

    Joined:
    Jul 27, 2010
    Messages:
    1,768
    Likes Received:
    6
    Have you check all the possibility. :hmmmm2:You can always move. I wonder if you were to relocate the O2s. Move the top one after the cat at the bottom and weld a bong after the second cat to relocate the bottom O2 :http://engine-codes.com/p0420_toyota.html
     
  3. Bang Bang

    Bang Bang New Member

    Joined:
    Sep 10, 2009
    Messages:
    310
    Likes Received:
    0
    O2 sims or ucon will get you a pass I've been doing it since 2011
     
  4. lvxr

    lvxr Member

    Joined:
    Feb 12, 2008
    Messages:
    934
    Likes Received:
    0
    and u pass smog?

    it needs to actually pass smog, not just get the CEL to turn off
     
  5. Slywhitty

    Slywhitty "Midget Magnet"

    Joined:
    Jan 26, 2008
    Messages:
    3,393
    Likes Received:
    8
    Do they do a sniffer/tailpipe test? Or do they just scan the computer?
     
  6. SgtBadA

    SgtBadA Active Member

    Joined:
    Apr 21, 2013
    Messages:
    583
    Likes Received:
    33
    They smog test meaning they check the tailpipe. I would try replacing the front two with some magnaflow ones that are 50 state legal. Never had a problem with using those on my cars
     
  7. Torspd

    Torspd Moderator
    Staff Member

    Joined:
    May 25, 2008
    Messages:
    14,814
    Likes Received:
    51
    Do you do a clutch or of something transmission related right before the codes? If so then try swapping the harness over. Might have the O2 harness wires attached to the opposite plugs that they are meant to be attached to.
     
  8. Toyota Tech

    Toyota Tech New Member

    Joined:
    May 8, 2015
    Messages:
    80
    Likes Received:
    0
    Also check for exhaust leaks. Stuff a rag in the tailpipe w/ it running and listen for puffing / hissing noises upstream.

    You could also try the "weapon r CEL eliminator" its a little elbow that you install in between the rear 02 sensor and the exhaust. Flat black it or something before smog so that its not obviously shiny and new. Been running them on my truck for years now, every once in a while under very specific cruising conditions I get a catalyst code, but other than that the monitor passes and therefor passes smog here. But all they do here is plug into your obd 2 port and check the monitors, all but evaporative monitor must be passed and then the computer determines the smog is ok pending a visual inspection, but this visual inspection does not require under vehicle inspection, only underhood, although the tech can choose to do so. One downside I have noticed with this, I pulled my 02 sensors the other day and because the 02 sensors aren't in the direct exhaust stream anymore they were covered in soot and carbon buildup, same with the little elbow. This could also possibly attributed to the lower operating temperature of the 02 versus the A/F ratio sensors (A/F ratios were also pulled @ the same time for inspection after seeing the rear 02's) but if you saw the extent of the buildup... doubtful, it looked like an EGR passage.

    Running the 02 sim from URD will also net a pass.

    I also have a full set of stock catalysts for sale, you would have to have your stock manifold welded onto these catalysts though unless you have a 2012+ xrunner.
     
  9. shane881510

    shane881510 Active Member

    Joined:
    Feb 14, 2010
    Messages:
    875
    Likes Received:
    32
    I have urd O2 sim. Plug and play. Used it for about two months. 100$ shipped.
     
  10. justin13703

    justin13703 Active Member

    Joined:
    Sep 9, 2010
    Messages:
    2,766
    Likes Received:
    14
    Guys his problem is that they are using a sniffer test. 02 sims will not make you pass a sniffer test. Just the computer scan test. 02 sims don't change the actual emissions in the exhaust. He's basically asking whether he should go with oem cats or high flow cats. Although it does sound a bit strange because I didn't think they did tailpipe tests on newer cars anymore.

    My opinion, I would keep an eye out for a set of factory manifolds and cats from someone who went with long tubes, maybe take Toyota Tech up on his offer. I'm not sure how effective high flow cats are when it comes to emissions and I'm not sure whether they would pass a sniffer test or not.

    And it is your front ones. The rear ones aren't monitored.
     
    #10 justin13703, Jun 29, 2015
    Last edited: Jun 29, 2015
  11. Toyota Tech

    Toyota Tech New Member

    Joined:
    May 8, 2015
    Messages:
    80
    Likes Received:
    0
    get the sensor simulator, or weapon r cel eliminator, install them and drive it like you stole it to the smog shop, if you get the catalysts hot enough it will still pass the sniffer test - although I live in cali and we no longer do the sniffer test so I would assume other states will be following suit?
     
  12. sixstringdave

    sixstringdave Member

    Joined:
    Jun 10, 2009
    Messages:
    939
    Likes Received:
    0
    I pass smog with my set up no prob. Only have 2 Hiflow Cats. The real ones.

    Its pretty strict here in the Liberal state of Washington.

    Been passing for quite some time now. Where are you located? It says two places in your info.
     
  13. lvxr

    lvxr Member

    Joined:
    Feb 12, 2008
    Messages:
    934
    Likes Received:
    0
    Sorry I didn't reply sooner. on newer vehicles they only use a computer scan. They dont actually put a sniffer into the tail pipe

    and i did this a few years back, and it solved my 02 codes, but currently im dealing with a new problem.

    --------------
    Being that they dont use a sniffer here in LAS VEGAS, it seems that my cheapest solution is getting a 02 sim, correct?
     
    #13 lvxr, Jul 1, 2015
    Last edited: Jul 1, 2015
  14. Slywhitty

    Slywhitty "Midget Magnet"

    Joined:
    Jan 26, 2008
    Messages:
    3,393
    Likes Received:
    8
    You got it. And I have an old O2 sim the one you splice into the harness (not plug and play) if you want it I'll let it go cheap but I'm in Canada and shipping prob wouldn't be worth it. Plus you have to solder it in
     
  15. Slywhitty

    Slywhitty "Midget Magnet"

    Joined:
    Jan 26, 2008
    Messages:
    3,393
    Likes Received:
    8


    Just re read this....... What the hell are you taking about?
     
  16. justin13703

    justin13703 Active Member

    Joined:
    Sep 9, 2010
    Messages:
    2,766
    Likes Received:
    14
    Well shit I thought you were saying they were using a sniffer test. If not then all you need is an O2 sim.
     
  17. lvxr

    lvxr Member

    Joined:
    Feb 12, 2008
    Messages:
    934
    Likes Received:
    0
    OK guys, so clearly the 02 sims will "fix" my codes and allow me to pass smog. will it have any long term problems?
     
  18. shane881510

    shane881510 Active Member

    Joined:
    Feb 14, 2010
    Messages:
    875
    Likes Received:
    32
    No down falls to it. Its great works good and does what it says it will do. I have a plug in play one. No cutting installs in about 15mins.
     
  19. lvxr

    lvxr Member

    Joined:
    Feb 12, 2008
    Messages:
    934
    Likes Received:
    0
    thanks. im getting that ordered tonight :top:
     

Share This Page

  • About Us

    XR-Underground is a dedicated community of Toyota X-Runner enthusiasts that was launched in January 2007. X-Runner Underground.com, referred to as XRU by our regular members, offers an active discussion forum, group events, specialty merchandise, a welcoming community of owners and the most information you can find about the Toyota X-Runner on the internet!
  • Quick Navigation

    Open the Quick Navigation

  • Like us on Facebook

  • Your donations keep XRU going

    XRU is a forum for the users, by the users. We receive very limited funding from vendors so we really rely on donations to cover our operating costs and to provide products and giveaways at events. Every dollar helps!

    If you are able to donate, we'd really appreciate your help.