2001 Audi A6 Emissions System

Tiny
SCOOL
  • MEMBER
  • 2001 AUDI A6
  • 6 CYL
  • AWD
  • AUTOMATIC
  • 97,000 MILES
My check engine light is on. OBD2 code P0430, P0420. I changed both driver's side O2 sensors. Mass air flow sensor looks good. Gas mileage seems normal. All 4 O2 sensors have off the chart ohm reading. With further OBD2 research I found: STFT Bank 1: 0.0%, LTFT Bank 1: 6.2%, STFT Bank 2: 2.3%, LTFT Bank 2 3.9%. What should I try next?
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Wednesday, April 22nd, 2009 AT 7:42 PM

3 Replies

Tiny
RACEFAN966
  • EXPERT
Ok with these codes together it is pointing at the Catalytic converters. The O2 sensors are picking up insufient flow. So I would call around to some shops that do exhaust and see if any can do a flow test to make sure but I think you will be replacing cats. Sorry and I hope this helps. Thanks and have a great day.
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Friday, April 24th, 2009 AT 10:39 AM
Tiny
SCOOL
  • MEMBER
Can you clarify? Any idea if I need two cats or just one? What do those oter 4 codes mean?
Are you're saying that P0420 and P0430 together mean I need new cats? Or are you saying that those in concert with the other 4 codes I mentioned mean I need new cats? Obviously, I'm not eager to spend $800+ on parts for a car that I hope to sell soon. Thanks!
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Friday, April 24th, 2009 AT 2:16 PM
Tiny
RACEFAN966
  • EXPERT
First off what other 4 codes you only have 2 list the P0420 and the P0430. These codes are for the primary cats and yes these codes are one for left and one for the right. This is why I said take it to a muffler shop and have a flow test done on it to determine if they are actually bad but according to the codes the cats are not effective enough. Now what you can try is to clean the mass air flow unit with mass air flow cleaner (NOTHING ELSE) and then clear the codes and see if they come back or not but I think they will. Now as for the other codes tell me what other codes you have as I only see that you listed the 2. If you do not have a code reader then check with you local parts store to see if they do a free scan to pull codes again and clear them after you get the codes that are pressent ok. Let me know what you find and we will go from there.
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Saturday, April 25th, 2009 AT 8:55 AM

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