TTDirk

Had this before, thought perished vacuum pipe fix on combi valve would fix it, nooot! What is the most common thing that goes wrong/fails with this system: Combi valve, solenoid valve or air motor or connections at one of them? Experiences?
I have Bentley instructions but what simple tests should I focus on first? I cannot get underneath the car easily.
Where is the solenod valve located?

TTinCT

it could have a slight tear in it. If it is a DVR, insure that the screw cap that covers the spring is pulled down tight....

TTagz

not positive, but I think so. Dealer replaced secondary air injection pump under warranty. Not sure if that's the only fix. It's just an emissions thing when the engine is cold, I would probably just ignore it or see if I could trick it.

Rocky-in-Connecticut

if your combi valve does not hold vacuum there is your problem.

TTDirk

What if I don't have a vacuum pump, suggestions?

TTDirk

O2 sensor fail/incomplete (car was not at full running temp yet)
seconday air inj fail,
Catalytic conv fail

TTDirk

Thanks, checked it last week, will take it out entirely, check and re-assemble

TTinCT

if you were in there last week...i betcha that is your problem...IMO

Rocky-in-Connecticut

it can take several complete driving cycles to reset readiness code. By one complete driving cycle I mean engine completely warmed up, driving on the highway for dozens of miles.

You could use Vag com to more quickly set readiness code.

Rocky-in-Connecticut

buy a $30 one or borrow.,