P0420 - Replaced Cat...What next?? - FirebirdV6.com/CamaroV6.com Message Board

Announcement

Collapse
No announcement yet.

P0420 - Replaced Cat...What next??

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • P0420 - Replaced Cat...What next??

    I replaced the cat and had the code reset... but the SES came back on for the same P0420 code some 50 miles later.

    I also have an exhaust leak that I cant identify and the mechanic believes its coming from my muffler.

    Would an exhaust leak AFTER the 02 sensor throw the code? What else could it be?
    1997 Camaro RS W/T-Tops<br />All Stock / 200 HP

  • #2
    Re: P0420 - Replaced Cat...What next??

    Could possibly be the post Cat 02 sensor going out - or a wiring issue but I think that would set a circuit code rather than a cat code.
    96 White M5 Camaro. Manual everything. Magnaflow cat, dynomax dual outlet axle back. Swapped to a disc rear with 3.42s and a torsen differential, kyb gr2 rear shocks, moog rear endlinks.

    Comment


    • #3
      Re: P0420 - Replaced Cat...What next??

      Originally posted by MegaHertz View Post
      Could possibly be the post Cat 02 sensor going out - or a wiring issue but I think that would set a circuit code rather than a cat code.
      Yeah... Its not running bad or anything, infact it runs better than ever and sounds amazing with my new bullet cat... I am very tempted to forgo the motor swap and just mod the V6 up.

      But, would a bad intake gasket cause this code? wouldnt I also be losing antifreeze? I can't smell exhaust in the engine bay so I dont think I have any cracked headers... what else could cause it?
      1997 Camaro RS W/T-Tops<br />All Stock / 200 HP

      Comment


      • #4
        Re: P0420 - Replaced Cat...What next??

        are you sure that the new cat itself is not throwing the code?

        I know some high flow ones will set off the ses light

        Comment


        • #5
          Re: P0420 - Replaced Cat...What next??

          Yeah - I was thinking that earlier. Did the cat come with emissions paperwork? My magnaflow did and it isn't setting any codes. Might have to tune it out if you're set on that cat.
          96 White M5 Camaro. Manual everything. Magnaflow cat, dynomax dual outlet axle back. Swapped to a disc rear with 3.42s and a torsen differential, kyb gr2 rear shocks, moog rear endlinks.

          Comment


          • #6
            Re: P0420 - Replaced Cat...What next??

            It could be the high flow cat just messing with things or the O2 sensor going bad. I would just get an emulator and call it a day. here is the one I got from ZZP, well worth the cheap investment.

            http://www.zzperformance.com/grand_p...ts1.php?id=967

            has worked great for me so far (about 2 years now), never had a prob with inspections either even with my cat delete.

            Comment


            • #7
              Re: P0420 - Replaced Cat...What next??

              The SES went off by itself...weird... no more code or anything and the car runs fine still...
              1997 Camaro RS W/T-Tops<br />All Stock / 200 HP

              Comment

              Latest Topics

              Collapse

              There are no results that meet this criteria.

              FORUM SPONSORS

              Collapse
              Working...
              X