Noman Mirza

Good evening friends,

I have a 2013 A6 3.0t and had a CEL code P0491 come up. I went to the dealership and they stated there was insufficient air flow from Bank #1 Combi valve. They are quoting $1300 to install a new valve. Should I fix it from the dealership? If so, is this a relatively easy fix that I should go to any mechanic for? Will I fail emissions if I don't fix it? Should I just not fix it and get the engine light removed to see if it comes back up again? My car is currently at 62k miles.

erionracing

i have the same issue i have a 2010 s5. first of all the combination valve is a bitch to change out. 2nd theres no way to determine if it has gone bad. 3rd check ur fuse box and hoses connected to the combination valve. sometimes a hose will just come loose...especially if there was engine work done previously. The fuses do burn out just around that 65k-75k limit. let me know if this was the problem.

erionracing

one other thing....there is no code for combination valve...it will either read secondary air injection system bank 1 or bank 2. the ecu can not read if the combination valve has failed. When the dealer tells you this they are making a guess and they change it out and check the hoses and fuses at the same time. In my opinion it is rare for the combination valve to fail.