Code P0420

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Jun 24, 2004 | 05:28 PM

RxNupe

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Posts: 111

From: Nashville, TN

Code P0420

The Autozone description says "Catalyst system efficiency for bank 1 is below threshold for the current engine operating conditions."

Is this a problem with oxygen sensors? I only have 37,000 miles.

Jun 25, 2004 | 08:35 AM

RxNupe

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From: Nashville, TN

HELLO????!!!!!

Jun 25, 2004 | 08:37 AM

shortdog273

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From: St. Louis, MO

It's one of your 02 sensors behind the cat.

Jun 25, 2004 | 08:40 AM

RxNupe

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From: Nashville, TN

I guess so...everything is in stock order

Jun 25, 2004 | 09:18 AM

2001NBMZ28

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From: Jacksonville, FL

It's either the rear driver's side 02 or the cat itself. The cat is covered under warranty for 8yrs/80K.

Jun 25, 2004 | 07:26 PM

mrr23

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Joined: Nov 2001

Posts: 1,151

From: orlando,florida,usa

when i got that code, i took it ot the dealer. they replaced the driver's cat. no more code. you have an 8/80k warranty on it. they'll replace it. mine went at 49k.

Jun 26, 2004 | 11:45 AM

RxNupe

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From: Nashville, TN

When I had my LT1 I could pull the PCM ign & batt fuses in order to reset the PCM to erase the code. I tried it with my LS1 and it didn't work. Are there any other tricks to resetting the PCM?

Jun 26, 2004 | 12:46 PM

2001NBMZ28

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Posts: 1,655

From: Jacksonville, FL

To reset:

Turn key on - don't start car.
Pull PCM BATT & PCM IGN fuses.
Wait 5-10 min.
Turn ignition off.
Replace fuses.

It'll work if the problem has been corrected.