PaulW

<center><img src="http://www.audipages.com/Tech_Articles/enginemechanical/vacuum1.JPG"></center><p>Got sick of my check engine light on....don't know if the vacuum hoses have anything to do with it...but I went to check them at the one way check valves that feed air into the exhaust on a cold start....they crumbled.

The small braided vacuum hoses are now all replaced.<ul><li><a href="http://www.audipages.com/Tech_Articles/enginemechanical/vacuumhosereplace.html">You can do it to!</a></li></ul>

airbil

I've had a cel for sometime and since my vagcom is flaky at best, I've just lived with it, but this seems like it is well worth the effort.
I wonder if the blue silicon hose from ECS Tuning is any better than the braided?
Thanks for the procedure!

PaulW

Just get the regular unbraided stuff for $15 at pep boys

gtreng1

Paul, Did you ever get the "to lean" code from the vacuum hoses?

PaulW

My check engine light started going on last fall, then off, then on, then off, and finally on.

I cleared the codes last weekend, here is what I have now:

Saturday,28,February,2009,15:19:44:13622
VCDS Version: Release 805.2

Address 01: Engine
Control Module Part Number: 4D0 907 560 AP
Component and/or Version: 4.2L V8/5V G 0001
Software Coding: 06753
Work Shop Code: WSC 02314
Additional Info: WAUGU54DX1N012848 AUZ7Z0A1817400
4 Faults Found:

17521 - Oxygen (Lambda) Sensor; B1 S1: Internal Resistance too High
P1113 - 35-10 - - - Intermittent
17538 - Fuel Trim; Bank 2 (Mult): System too Lean
P1130 - 35-00 - -
17539 - Oxygen (Lambda) Sensor; B2 S1: Internal Resistance too High
P1131 - 35-10 - - - Intermittent
17536 - Fuel Trim; Bank 1 (Mult): System too Lean
P1128 - 35-00 - -

A8CT

o2 sensors are new and so are all the vac lines.

I get the CEL, reset it and it might stay off for 300-400 miles. BUT, my car doesn't feel quite right so I want to figure it out.

I'm gonna swap in my "old" MAF tomorrow and see if the readings change.

Bob

mAgnum8

Once again, THANK YOU VERY MUCH for the footwork and write up.

gtreng1

..to fix it though. I have the parts.

ricoblanco

<a href="https://forums.audiworld.com/a8/msgs/165940.phtml">additional codes</a> I gleaned from an Audi TSB for the 40V. Also in the FAQ. HTH.

PaulW

Okay, I'm blind, where is it?