Question

2000 Audi A6 4.2L with both P0422 and P0432 codes throwing check engine light. used a scanner to monitor o2 sensors and they seem to be responding like they should..front O2's fluctuating and back O2 senors are rock solid at .435 volts...

does this determine that the cats are performing properly?

How do I proceed to get the check engine light to stay off.... I'm in upstate new york and we have inspections that a car will not pass with a check engine light on

Answer 1

You could start by using high-octane gas for a couple of weeks, if you are already using high-octane gas, then you can check for intake or exhaust leaks. If the problem persists, is highly likely that the problem is the Catalytic Converters.

P0422 Audi Code - Main Catalyst Efficiency Below Threshold Bank 1
Read more: https://www.autocodes.com/p0422_audi.html

P0432 Audi Code - Main Catalyst Efficiency Below Threshold Bank 2
Read more: https://www.autocodes.com/p0432_audi.html