P0420 CEL Code
10-27-2008, 06:50 PM
#1
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Join Date: Oct 2006
Location: Atlanta, Georgia
Posts: 163
P0420 CEL Code
Hey guys. Been a while since I posted on here but got a problem. My car is throwing code P0420. Did a little digging and it appears that most people get this code after swapping over to after market headers. Problem is that I haven't swapped the headers. I have an Injen intake and Tsudo N1 Catback exhaust on the car and that's it. So my question is what is possibly throwing the code? Do I need a new cat? Any insight into this would be most helpful.
10-27-2008, 09:02 PM
#4
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Join Date: Jul 2004
Posts: 760
just put your new headers on. the Anti-Fouler spark plug trick should substitute the error your getting with your cat. but that is if your planning on removing the cat, unless you want to leave it broken, if it is....
10-28-2008, 02:14 AM
#10
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Team ScioNRG
Join Date: Sep 2007
Location: Rhode Island
Posts: 592
yeah if you have no header and it's give you a 420 code it ha to be a bad cat. bad o2 sensors would throw a 02 code. tough luck man. maybe it's something to do with your intake. i don't have an intake nor do i have cats haha.
10-29-2008, 10:40 PM
#14
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Location: South Florida
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lol - I think you're the guy that runs that website - or you're in some way affiliated.
You have 4 posts as of right now, 6:40pm EST 10/29/08 and all 4 posts were directing people to that website.
Just get yourself a vendor log-in from the admins.
You have 4 posts as of right now, 6:40pm EST 10/29/08 and all 4 posts were directing people to that website.
Just get yourself a vendor log-in from the admins.
02-09-2009, 11:03 PM
#15
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Join Date: Jan 2005
Location: west palm beach FL
Posts: 27
that is a no biggy code really. i just got the same code yesterday, im completely stock no headers, i just cleared it, waiting if it comes back. this coded does not necessarely mean you have a bad cat, its more emission based.
just see if it comes back.
just see if it comes back.
02-09-2009, 11:55 PM
#16
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Balliztik
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Join Date: Jun 2007
Location: Washington
Posts: 9,538
check the seals on the intake and the seals on the exhaust,also check to see if your PVC valve is loose,any of these things can cause that CEL as well,to much air getting in past the MAF sensor and the engine will toss out a code for cat failure.
03-09-2009, 07:19 PM
#17
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Join Date: Mar 2009
Posts: 2
p0420 (cel) code
just put my headers on and have an intake on my tc, I did the anti-fouler trick on the car but still pulled the p0420 code, when I replaced the headers I did the antifouler all at once and didn't reset the car thinking that the car wouldn't see a problem if I did it all at once, do I have to just reset it for it to go away? Thank u fellers... 
