alfam8

hello guys,
i've read almost everything i could find but am still stumped- i would greatly appreciate if someone who had this issue would help out.
car is a 2004 3.0 v6 avant.
after a long trip engine check light came on as 0171- i checked all vacuum hoses, ran several tanks of gas with injector cleaner, reset the computer with a scanner and issue went away.
several weeks later the issue returned, now with both 0171 and 0174 codes indicating both banks running lean- again, i looked for vacuum leaks, ran a scan of o2 sensors while car was running and everything looked normal. basically now the car will be fine for 2-3 days before throwing the same codes, there is no rough idle and no abnormal operation of secondary air pump. out of curiousity (and to gage dealer's input / honesty) i sent the wife to audi dealer for a scan with factory computer- she came back with the following 'quote':
-found codes for vacuum pump for brake system and intake runner and solenoid unit under the intake manifold.

i guess if the brake vacuum pump is leaking that would possibly allow more air in and cause the lean code. what about the intake runner and the solenoid? is that a common deal?
thanks for any educated input.
regards.

ddillenger

Get vcds, and do a full scan. That should be a bit more illuminating.

alfam8

thx,
what is a vcds, i am not familiar. i have the acutron scanner.

alfam8

nevermind, i looked it up.
thx