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post #1 of 10 (permalink) Old 10-04-2010, 06:31 AM Thread Starter
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P.O. 420 Code

alright guys I just got this check engine pop on and my code reader is saying it's the po 420. Does anyone know how to fix this problem?
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post #2 of 10 (permalink) Old 10-04-2010, 06:52 AM
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P0420 DTC Code - Catalyst System Efficiency Below Threshold (Bank 1)

It could be a number of things. Check em all before you go purchasing things. Had this problem myself

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post #3 of 10 (permalink) Old 10-04-2010, 07:31 AM
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Maybe your car is craving some herb.


J/K, hope you figure out what the code is man.
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post #4 of 10 (permalink) Old 10-04-2010, 08:52 AM
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This may sound strange, but does your car stink? What I mean is does it have any kind of strange odor to it after it fully warms up and you are driving around?

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post #5 of 10 (permalink) Old 10-04-2010, 08:56 AM
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If you have a catless downpipe or even a highflow cat the odds are that that's the reason why you're throwing that code. A tune can fix that. You're o2 sensor that runs on your header may need to be replaced also.


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post #6 of 10 (permalink) Old 10-04-2010, 08:57 AM Thread Starter
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no odors, before when I blew a gasket for sure I noticed an odor, but after fixing it it went away. I do have a high flowing cat though. Would you suggest an HPTuners or a Trifecta tune though
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post #7 of 10 (permalink) Old 10-04-2010, 09:07 AM
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Hp tuners have no support for the 2.2. You would need to go with trifecta. I would try replacing your o2 sensor first and see what happens seeing that your code is saying bank 1


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post #8 of 10 (permalink) Old 10-04-2010, 09:07 AM
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Before you get to doing a tune you might want to look at the cat for physical damage or discoloration. A lot of shops can also test o2 sensors pretty cheap.

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post #9 of 10 (permalink) Old 10-04-2010, 09:42 AM
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and clear the code and see if it comes back



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post #10 of 10 (permalink) Old 10-04-2010, 12:10 PM
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Quote:
Originally Posted by dkscbalt View Post
Hp tuners have no support for the 2.2. You would need to go with trifecta. I would try replacing your o2 sensor first and see what happens seeing that your code is saying bank 1
I wouldn't replace the o2 sensor. They're $80. Ain't cheap. If u still have ur stock dp then I would try installing that and check to see if the code pops up. You will have to clear it tho

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