Question about 2003 Audi A6

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2003 A6 Runs very rough have a hand held obd II diagnostic reader with a code po 431 warm up catalyst below threshold bank 2 is it just plugs ?

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  • xhybrids8com Nov 23, 2008

    I got the same problem, I had it at about 75k and the dealer is suppose to replace the cat for free if it the car is under 80k (at least here in california), however turns out dealer will give free check first and just reset the code, if it comes up second time and the car is under 80k the dealer will replace it for free. In my case it is too late as it came on at 85k, but if you are below 80k you might wanna look at local laws. Good luck

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No, it's either a clogged catalytic converter or, more likely, a bad secondary O2 sensor on the driver's side. The secondary sensor is the one after the catalytic converter, which is used to measure its efficiency. When that sensor fails, the computer can't judge how well the cat is working and often throws a code such as this. However, it should also throw a failed O2 sensor, sensor 2 bank 2, at the same time. You may have a bad cat, but if it comes down to replacing parts, I'd do the sensor first - it's about 15% of the price of a cat.

You could take the two secondary sensors and swap them - move the left side one to the right side and vice versa, clear the code, then scan the car again after running and see if the code comes back the same. If it does, your cat is bad. If it comes back reading a problem on bank 1, it's the sensor.

Posted on Oct 03, 2008

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What means catalyst Efficiency below normal


      Got it scanned and it's P0420: Catalyst efficiency below thresholdbank 1. They said it could be a bad catalytic converter or oxygen sensor. I borrowed a scanner and tried to measure the oxygen sensor readings over time.Sep 8, 2011

      civic - Check Engine code P0420 Catalyst efficiency below ...

      mechanics.stackexchange.com/.../check-engine-code-p0420-catalyst-efficie...
    Feedback

    P0420 Error Code: Catalyst System Efficiency Below ...

    www.obd-codes.com/p0420
    P0420 OBD-II Trouble Code. Technical Description. Catalyst System Efficiency Below Threshold (Bank 1). What does that mean? This diagnostic trouble code ...

    P0420 Code Fix How Its Done Catalyst Efficiency Below ...

    ? 4:25
    https://www.youtube.com/watch?v=-c8090n1Ihs
    Jun 20, 2014 - Uploaded by ACE AUTOS UK
    Here is a tutorial on P0420 code fix catalyst efficiency below threshold How To Diagnose a p0420 code ...

Jan 26, 2016 | Cars & Trucks

1 Answer

Where should i find this sensor P0342?


EXHAUST RELATED ERROR CODES

There are 711 possible PO generic DTC error codes. Only 7 of the 711 codes are exhaust related.

PO401: Insufficient EGR Flow

PO402: Exhaust Gas Recirculation (EGR) Excessive Flow Detected

PO410: Secondary Air Injection System Malfunction

PO420: Catalyst System Efficiency Below Threshold (Bank 1)

PO421: Warm-Up Catalyst Efficiency Below Threshold (Bank 1)

PO430: Catalyst System Efficiency Below Threshold (Bank 2)

PO431: Warm-Up Catalyst Efficiency Below Threshold (Bank 2)

THINGS TO ASK YOURSELF OR YOUR CUSTOMER

Have there been any driveability or performance issues with the vehicle, have there been any recent repairs or tune-up work performed, if so was the check engine light reset and were the codes recorded on previous repair orders.

Do not rely on scan tool data alone. In most applications, the customer will have the check engine light reset prior to repair. If the original cause of converter failure is intermittent, only the catalyst failure code may show up (masking the original reason for converter failure).

Nov 04, 2012 | Chevrolet Epica Cars & Trucks

1 Answer

What does a po430 code mean on a mercury cougar


EXHAUST RELATED ERROR CODES

There are 711 possible PO generic DTC error codes. Only 7 of the 711 codes are exhaust related.

PO401: Insufficient EGR Flow

PO402: Exhaust Gas Recirculation (EGR) Excessive Flow Detected

PO410: Secondary Air Injection System Malfunction

PO420: Catalyst System Efficiency Below Threshold (Bank 1)

PO421: Warm-Up Catalyst Efficiency Below Threshold (Bank 1)

PO430: Catalyst System Efficiency Below Threshold (Bank 2)

PO431: Warm-Up Catalyst Efficiency Below Threshold (Bank 2)

THINGS TO ASK YOURSELF OR YOUR CUSTOMER

Have there been any driveability or performance issues with the vehicle, have there been any recent repairs or tune-up work performed, if so was the check engine light reset and were the codes recorded on previous repair orders.

Do not rely on scan tool data alone. In most applications, the customer will have the check engine light reset prior to repair. If the original cause of converter failure is intermittent, only the catalyst failure code may show up

Nov 04, 2012 | Cars & Trucks

2 Answers

The obd II code is po 430. what does that have to do with the catalyst system or emmission?


PO430--Catalyst System Efficiency Below Threshold (Bank 2)

On your vehicle ,that would be a bad exhaust converter
on the drivers side

Bank 1 would be where the #1 cylinder is
Bank 2 the opposite on a V6 or V8

Your converter is about 12 or 13 years old
They should last about 12 to 15 in my opinion

I would replace both converters and both O2
Sensors--if they have 100,000 miles on them

The Catalyst is the material inside that converts
the exhaust gases to Water Vapor, H2O, and reduces
HC,CO,and NOX

Feb 14, 2011 | 1998 Mercury Grand Marquis

1 Answer

1997 Mercury Mountaineer What is Catalyst Efficiency Below (Bank


it means the catalyst is worn out, the efficiency is monitored by sensors, when the Cat falls below a certain reading or "threshold" the code is generating telling u that u need a new catalytic converter.

Feb 18, 2010 | 1997 Mercury Mountaineer

3 Answers

I had my car inspected and received P0420 code? what does it mean?


P0420 Error Code: Catalyst System Efficiency Below Threshold (Bank 1) Repair information for the OBD-II trouble code P0420 - Catalyst System Efficiency Below Threshold (Bank 1)
www.obd-codes.com/p0420

Feb 18, 2010 | 2000 Toyota Celica

2 Answers

What are codes P1492, P0421 & P0431 on the 2002 Mazda Millenia?


po421 warm up catalyst efficiency below threshhold bank 1, 431 same on bank 2..

Feb 08, 2010 | 2002 Mazda Millenia

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