Fault codes:P0431,P0421,P1603-intermittent?

[SchwarzS6]

And if you do need new catalytic converters there are local companies which recore the OEM cats. I used Connecticut Catalytic a number of years ago. I think the cost was about $350/cat compared to what was $900 at the dealer at that time.

[kwilli39]

p0421, p0431, p0441

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I am getting these three codes and have been told that my cat needs to be replaced. Is this true? Also how much would this cost at a dealer? I have 2003 3.0 a4 cabrio. 95xxx miles

The reason i ask is if there is something else i could try, say checking o2 sensors the difference in price is enormous..

thanks.

[kwilli39]

Originally Posted by xavisu1

Hello Audi world,
I am new to this world. I bought a 2002 A4 3.0L and one pf my friends scan my car. I had all those P0421, and P0431 but in my case their static. These codes mean I need to buy new catalyc converters? If so, where can i buy them there $ 1,200 a piece at the dealer.

Thank you so much for your help.

I have 2003 a4, 3.0L and i believe my cat is bad too. Audi would replace for free if under 80k miles i believe. Unfortunately I bought it with 83 and am now at 95+... However I do have a local audi mechaninc I use for everything and he told me he would do it for around $1200 total including labor using oem parts. So if by any chance you live in the chicagoland area I could give you his info.

He lives a little far from me and I want to know if it makes sense to check other things first, like o2 sensors, before I commit to replacing the cat but I am pretty sure thats what I am going to have to do...

[Dector22]

Warm Up Catalyst; Bank 1: Efficiency Below Threshold / Intermittent
5 times in last two months after being cleared each time.

Secondary Air Injection System; Bank 2: Insufficient Flow / Intermittent
6 times in last two months after being cleared each time.

Secondary Air Injection System; Bank 1: Insufficient Flow / Intermittent
6 times in last two months after being cleared each time.

[02ALLROAD02]

My CEL is on and I found someone on vagtoolfinder.com to scan for codes and it came up with:

Address 01: Engine Labels: 078-907-551-AZA.lbl
Control Module Part Number: 4Z7 907 551 M
Component and/or Version: 2.7l V6/5VT G 0001
Software Coding: 06752
Work Shop Code: WSC 01013
Additional Info: WA1YD64B52N142060 AUZ7Z0B2112510
VCID: 4D9B746087CA049
4 Faults Found:


17522 - Oxygen (Lambda) Sensor; B1 S2
P1114 - 35-00 - Internal Resistance too High
17526 - Oxygen (Lambda) Sensor Heating; B1 S2
P1118 - 35-00 - Open Circuit
17524 - Oxygen (Lambda) Sensor Heating; B1 S1
P1116 - 35-00 - Open Circuit
16518 - Oxygen (Lambda) Sensor B1 S1
P0134 - 35-00 - No Activity


I installed four new o2 sensors and it took a day for the CEL to clear itself. Three hours later all the codes came back with an additional code for the MAF reading low. I'm lost! could it be the ECM?