Hey I tried this, disconnected the downstream sensors and I got codes
P1122, P1118 - bank1/2 sensor 2 open circuit and P1114,P1140 Bank1/2 sensor 2 internal resistance is too high. I expected the first codes but not the second two.
The running rich codes still came on right away. I want to say the car ran better when I disconnected the downstream sensors. I did not see the code for the MAF - internal resistance too high P0103 but it usually takes a couple days to come on.
I think there is a vacuum leak (or pressure leak this system is pressurized?) that is causing this and I do not know if there is something else like the fuel injectors contributing. I sometimes smell a burn smell in the car.
Appointment tomorrow with the stealership. I am telling them to either inspect my car or give me all my money back and I will pay for the spark plugs they put in. I had it with them they are supposed to be audi experts they are crap.
Originally Posted by Flyboy
The secondary O2 sensors are also able to affect the reported AFR. If they are reading incorrectly that might be causing the ECU to run rich.
Possibly try disconnecting the secondary o2 sensors, clear the codes and see what happens. You'll probably throw a cat efficiency fault code, but it might give you another data point for what might be affecting things.