I'm right now throwing what i think is a o2 sensor CEL, P0144.

From what I can see in other threads an research it means "Bank 1 Sensor 3".

But, I thought
Bank 1=Driver Side & 2=Passenger and that
Sensor 1=precat and sensor 2=postcat

What is Bank 1 sensor 3??

Thanks in advance for the help.

99.5 A4 Avant Quattro 2.8

 

Not sure, but you might have like one in the exhaust manifold, one right in front of the cat, and one right behind the cat?

 

P0144 is a generic O2 sensor overvoltage. Bank 1 is passenger side (that's where cylinders 1-3 are). That would indicate a problem with the passenger side post-cat O2 sensor.