J. Patterson

Schwing, and others,
This AM prior to 5 mile drive to work, I unplugged MAF as suggested.
1. I notice that this causes ESP light to come on.
2. no real increase in boost in APR 93 or stock.
Engine seems just a bit crisper but it's cool this morning. 39 degrees.
3. After 3-4 miles I get CEL.

I have reconnected MAF lead. Will CEL reset on it's on? Can ECU be "reset" by unplugging it for a period of time? Should this be done?
You guys talk about a Bently? manual. Does it have troubleshooting procedures? What about VAG com? I see references to software for laptops, and have seen software for Palm (handspring visor ect) too. Suggestions?
I enjoy machinery and I am sure I can learn what I have to to take care of this, but time is limited. Didn't really need to start this aggravation. If you can help me to stop it I will be eternally grateful.

J. Patterson

ebb(in memorium)

and unplugging it will reset the codes (but gives you low voltage one, which does not affect performance).

But if you get a CEL I think it's something more than an MAF...

A trip to the dealer in order?

Why not find someone with a vag-com to see what codes you have thrown b4 resetting the ecu?

TTinCT

it will clear the CEL if you go to the car and switch ignition on and off, pausing in between, 3 or 4 times. Do not start the car, just get it into the run position.
Should clear relatively quickly.

VAG is a great tool, but caution is advised as you can really screw up the car, if you play with settings you do not know about.....fwiw....

TTschwing

On whether unplugging the MAF got you back to where you were before the problem or not??

Don't worry about the cell...It will go away, but really, having a VAG-Com for these cars is almost a necessity so you can clear codes, run diagnostic routines etc. If you had one, I could point you to measuring blocks that would tell us more...

Also, do you have the latest green temp sensor in? $6 part, 10 minute swap. They have a high failure rate and cause a symptom like this (IE telling the ECU things are hot when they're not), and subsequently dialing down boost...<ul><li><a href="http://www.ross-tech.com">Vag Com Originators</a></li></ul>

J. Patterson

Thanks for checking on me. No, I am still down on boost. Disconnecting MAF had no effect other than the ESP and CEL lights. Those have cleared now. I guess I am headed for a trip back to APR to let them figure out what happened. I have ordered a factory DV and will pick it up tomorrow. I still don't see how it could cause these symptoms as it appears only to open when the throttle closes and creates vacuum on the diaphragm. I can see how one could leak boost thru the valve, but mine appears good. Looks like boost would work with the spring rather than against it in the stock position. Am I right?
I expect that I am in some sort of limp mode that only a VAG can diagnose. I'll let you know. Thanks for your help and concern.

J. Patterson

TTinCT

how are you determining that you are down on Boost? Does the car feel slower, or do you have a gauge that is showing lower boost levels???

If its the latter, then you should know in the cooler weather, boost can drop by as much as 4 lbs due to colder air.....

J. Patterson

TTinCT ,
While I don't have a boost guage, The symptoms say boost is way down. I was chipped last Thurs. Saturday morning the car went way slow. Slower than stock. Switching from APR 93 back to stock makes no detectable difference. I posted the whole story last night . It is back a ways.
Thanks,
J. Patterson