First time post, but have been lurking around here for a while. You guys know your Audis! I'd like to get some help too, if you all have got the time.

I just bought the VAG COM cable after my check engine light came on last week in my 2000 2.7t A6 and it was pulling fault codes for low air flow for secondary air input and failed O2 sensor in the exhaust.

How does a guy go about checking the vacuum system? There just seem to be so many hoses all over the place...and forget trying to find a leak when the engine is on! (that's my thought anyways).
Any good tips on where to start and how to actually fins leaks (if any)? Thanks!

 

BTW -

more info, I cleared the codes and the same ones came back after starting the engine for the 2nd time after.

 

Usually secondary air problems are easy to fix, but it depends upon the vehicle.
The O2 code might be because the air pump is not working.

Ever consider getting a repair manual?

 

Here's how I do it. I take a can of carb cleaner. Take off all of your decorative covers. and mist it, DON"T spray it like a mad man, just mist it over the lines and if the engine idle picks up you have a leak. Start to hone in on it. I notice anything rubber over time just falls apart after a while. (usually when I touch it to see if it is broken it breaks) I you havent replaced your valve cover gaskets lately that would be a good thing to do for peace of mind and keep the driveway clean