meternerd

I borrowed a code reader/resetter because my CEL came on. It doesn't give P...codes, but a 4 digit code and a manual that tells you what the code means. It's supposedly Audi/VW specific. Anyway...the codes (two) mean Bank1 (and Bank 2) Mixture adaption (add.) System too lean. I looked in my Bentleys manual and can find no codes that match this one. It's a 2001 A6 2.7T. I changed the fuel filter, thinking lean means too little fuel, but the same two codes keep coming back. Car runs great, but I have a smog test coming up and a CEL is an automatic fail. I know I'll get all kinds of responses about buying a Vag Com, but times are kinda tight right now, so that's not an option. Any ideas? Thanks in advance.

4Driver4

Have you checked for vacuum leaks?
Diverter valves functioning?

meternerd

You nailed it. Vacuum leak. Cracked fitting. I epoxied it for a fix, because I have no idea what it is, an it looks like a bear to remove. Thanks for the nudge in the right direction. I haven't tried it yet, but it was making a pretty loud hissing noise at idle, so I'm betting that's the fix.

4Driver4

Check valve. I'd replace that.

SloopJohnB@mac.com

Heck...if the epoxy works, leave it. You'll need to clip those OEM clamps to get it out, much less remove stuff in the way...and risk breaking other plastic bits and discover leaking vacuum hoses on the way in....but hang in there...leaking hoses happen.

Unless you get a handful of OEM crimp clamps (available from your local audi dealer, make sure you get the right diameter ones as well as a crimp tool..similar to a pliers used on CVJ boots...if you don't have one you should anyway for CVJ boots...) you'll be crowded in there with worm drive clamps.

meternerd

Well, my wifey took it on a long ride around Lake Tahoe today and no CEL. Runs perfect, so I figure it works, so I'll leave it as is. "If it ain't broke....fix it 'till it is!" Naw!

meternerd

This was posted quite a while ago, but right on. The epoxy did not hold. I have a new valve on order. Apparently they have upgraded the part, because the new part number is different. Pictures look identical to mine, though.

Symptoms were..MIL (same codes as before), engine missing and a "clunking sound" coming up our big hill by home. Symptom was by way of my wifey. I suspect the missing engine caused the tranny to make a noise. I hope!

Part is kinda scarce, so I had to order it out of Virginia. If I plug the vacuum line from the motor, could I drive it without damaging anything? It's the only car we have with air conditioning, and it's HOT!

SloopJohnB@mac.com

So clean it up again and use epoxy. I like JBWeld. You might also wrap it in metal duct tape. At least until your new part comes in.