A4 Phil

'02 S6. 120K miles. Throws a pretty regular P0430 (Catalytic converter system, bank 2 - efficiency below threshold) every few weeks or so.

What are the latest thoughts on this?

Replace the cats? Replace just the O2 sensor?

If I replace the cats, any recommendations on brands?

clancy

Have you searched here about anti foulers?

SloopJohnB@mac.com

However, it's not unlikely the cats need replacement. You could kluge the system with aftermarket cats but I'd use OEM ones. They're spendy, but keep up the value of the car. Some people would argue that you'll never get out of the car the cost of two new cats on an 02S6, but I wouldn't touch an S6 with aftermarket cats without a $4K or better drop in price from what I would pay for one that had OEM cats and no MILs.

Audi had trouble with these cars and extended the cat emission warranty from 8/80 to 10/100….I had one of mine replaced under the 10/100 (over 8 years old but under 100k at the time) and a year or so later replaced the other with a OEM cat.

dwengi

Dealer may be able to refresh ECU on a '02 to increase the threshold.

I did both 02 sensors and anti-foulers at the same time and the code went away.

A4 Phil

Currently in discussions with AudiUSA and dealer.

Two dealers noted same code while under the 1/100. They simply cleared codes and serviced vacuum related issues. Now car is out if warranty but code exists and they want 6K to replace cats. We will see. Even a discount would be appreciated.