P0420 code CES light on Exactly 1 Year after dual exhaust swap at Meineke

i-bought-a-v6 · August 10th, 2011, 09:31 PM

So after exactly 1 year of swap, my CES light comes on and autozone gives me the code P0420, What do I do keep in mind i live in new york and need to pass inspection

mcqueen · August 10th, 2011, 09:36 PM

Got this list from another forum. Possible causes:

Use of leaded fuel.
Oil contamination.
Cylinder misfiring.
Damaged HO2S.
Damaged ECT sensor.
Downstream HO2S wires improperly connected.
Fuel pressure too high.
Damaged exhaust system pipe.
Damaged exhaust manifold.
Damaged muffler/tailpipe assembly.
Damaged catalytic converter.

i-bought-a-v6 · August 10th, 2011, 09:37 PM

Originally Posted by mcqueen

Got this list from another forum. Possible causes:

Use of leaded fuel.
Oil contamination.
Cylinder misfiring.
Damaged HO2S.
Damaged ECT sensor.
Downstream HO2S wires improperly connected.
Fuel pressure too high.
Damaged exhaust system pipe.
Damaged exhaust manifold.
Damaged muffler/tailpipe assembly.
Damaged catalytic converter.

I know, but what do I do BTW its bank 1

mcqueen · August 10th, 2011, 09:39 PM

Honestly, I would put my money on the rear passenger (bank 1) O2 sensor being bad. You're probably at or past the point when O2 sensors are supposed to be changed (100k miles).

i-bought-a-v6 · August 10th, 2011, 09:40 PM

Originally Posted by mcqueen

Honestly, I would put my money on the rear passenger (bank 1) O2 sensor being bad. You're probably at or past the point when O2 sensors are supposed to be changed (100k miles).

yeah im at 86k, but is it possible that the shop screwed up and a year later my exhaust goes bad, becuase i realized that my rattle also went away

mcqueen · August 10th, 2011, 09:42 PM

I doubt it was anything caused by the shop. If they had damaged something, it probably would have been apparent not long after the work was done.

i-bought-a-v6 · August 10th, 2011, 09:44 PM

Originally Posted by mcqueen

I doubt it was anything caused by the shop. If they had damaged something, it probably would have been apparent not long after the work was done.

ok, thats what they said, should i just get slp high flow cats?

i also need to pass emissions

mcqueen · August 10th, 2011, 09:46 PM

I've never had to deal with emissions so I'm not sure if high flows will pass but if they will and you get them, they may not clear up the problem (because it might just be that the O2 sensor has gone bad). But I'll let someone who has emissions in their state chime in about the high flows.

1slowv6 · August 10th, 2011, 10:00 PM

why do people always wanna jump on the last shop to do work on their car even if it was a year ago...

working at a shop i see this alot..... and no its not the shop if its been a year. i imagine its something unrelated to the 02's because 80% of the time on our cars that passenger manifold will be cracked letting air into the system throwing off the 02 sensors readings.

i had this EXACT code when mine was cracked

mcqueen · August 10th, 2011, 10:03 PM

^ That's possible as well, and pretty easy to check with some soap and water in a spray bottle.

6ER THEN I 8ER! · August 10th, 2011, 10:20 PM

just wow about blaming the shop....

as for your issue...and you wondering about hi-flow cats...if they are marked OBD2 complient then they will work for emissions. as for your code clean off the driver side o2 sensors with a wire brush...reset the computer then do a drive cycle...you might get off lucky

mcqueen · August 10th, 2011, 11:26 PM

Originally Posted by 6ER THEN I 8ER

just wow about blaming the shop....

as for your issue...and you wondering about hi-flow cats...if they are marked OBD2 complient then they will work for emissions. as for your code clean off the driver side o2 sensors with a wire brush...reset the computer then do a drive cycle...you might get off lucky

You mean passenger. Unless I've gone totally crazy, I'm pretty sure bank 1 is passenger side

6ER THEN I 8ER! · August 11th, 2011, 01:01 AM

Originally Posted by mcqueen

You mean passenger. Unless I've gone totally crazy, I'm pretty sure bank 1 is passenger side

nope you're correct...i wasn't paying attention lol

mcqueen · August 11th, 2011, 01:06 AM

6ER THEN I 8ER! · August 11th, 2011, 01:09 AM

Originally Posted by mcqueen

you try having my avi and not making a mistake

August 10th, 2011, 09:31 PM	#1
i-bought-a-v6 Banned 2002 Auto V6 Several Seconds Join Date: May 2010 Location: NY Posts: 1,096 iTrader: 0 reviews	P0420 code CES light on Exactly 1 Year after dual exhaust swap at Meineke So after exactly 1 year of swap, my CES light comes on and autozone gives me the code P0420, What do I do keep in mind i live in new york and need to pass inspection __________________ [U]Specs[/U] 351W EFI with 2 cylinder delete [U]Mods[/U] Catted dual exhaust with Flowmaster 40's H-piped $60 XM with no subscription Savings Account Mod $00000.00 [U]Future Mods[/U] None [COLOR="Red"]Put This Immature Crap Back In Your Sig, And You'll Be Taking A Vacation. Love, TheUNZippee!T[/COLOR]

August 10th, 2011, 10:00 PM	#9
1slowv6 Enthusiast 2000 v6 mustang Join Date: Nov 2010 Location: St. petersburg FL Posts: 738 iTrader: 1 reviews	why do people always wanna jump on the last shop to do work on their car even if it was a year ago... working at a shop i see this alot..... and no its not the shop if its been a year. i imagine its something unrelated to the 02's because 80% of the time on our cars that passenger manifold will be cracked letting air into the system throwing off the 02 sensors readings. i had this EXACT code when mine was cracked __________________ If Nissan motorsports is Nismo..Wouldn't Honda motorsports be Homo?

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August 10th, 2011, 10:20 PM	#11
6ER THEN I 8ER! Banned Join Date: Apr 2007 Location: Portland, TN Posts: 17,515 iTrader: 3 reviews	just wow about blaming the shop.... as for your issue...and you wondering about hi-flow cats...if they are marked OBD2 complient then they will work for emissions. as for your code clean off the driver side o2 sensors with a wire brush...reset the computer then do a drive cycle...you might get off lucky

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