Just been informed that I need to replace both catalytic converters on my 2000 A6 Avant. As luck has it, Iâ€^TMm at 86,000 miles (Converters are covered under warranty up to 85,000). Of course my extended 100K warranty bought from the dealer does not cover it. Audi wants 3K just for the converters. By the time I get new Oxygen sensors and Labor, Iâ€^TMm sure it will be up to $5,000. Has anyone replaced their converter with non-factory units such as some of the â€oehigh-flowâ€� performance models? Would this void the rest of my 100K warranty? Thanks,
JS

I too have had to do the same thing but was told a different line of bull from Audi. I replaced one side with aftermarket cats and pipes and sensors and am still pulling the same code. No fluid loss so I do not think I am ruining cats by filling them up with junk. What IS going on would be nice. The code I am pulling are P1176 and also P1177 for both sides. Could I have a Exhaust manafold problem like a leak as well? If anybody has any info I would appreciate it.