midnightgolfer

Hi. I'm hoping someone out there has had experience with a similar situation, and could make a recommendation for me.

I just replaced the MAF sensor with a brand new one, and I'm still getting the MAF error code coming back, as well as the O2 sensor error codes, and the AutoTrans related error code.

Is it more likely that I got a bad new MAF sensor, or that there's something else more common going on. How likely is it that the O2 sensors are going to give me the same hassle, if I were to buy new ones and replace them, too?

Any ideas are welcome.

P.S. It's a Euro 1996-1997 A8 Quattro with the AEW 3.7 L engine, if it makes any difference.




Below I have copied the relevant VAG Com codes.

Chassis Type: 4D - Audi A8 D2
Scan: 01 03 08 11 15 16 17 18 25 35 37 45 55 56 57 65 67 75 76 77
02

Mileage: 162340km/100873miles
-------------------------------------------------------------------------------
Address 01: Engine Labels: Redir Fail!
Part No: 4D0 907 557 A
Component: 3,7L V8/4V MOTR AT D04
Coding: 04253
Shop #: WSC 02314
VCID: 2A55FD5AFC6F

4 Faults Found:
16486 - Mass Air Flow Sensor (G70): Signal too Low
P0102 - 35-00 - -
16518 - Oxygen (Lambda) Sensor B1 S1: No Activity
P0134 - 35-10 - - - Intermittent
16538 - Oxygen (Lambda) Sensor B2 S1: No Activity
P0154 - 35-10 - - - Intermittent
17541 - Oxygen (Lambda) Sensor Heating; B1&B2 S1; Heating Circuit: Elect. Malfunction
P1133 - 35-00 - -
Readiness: N/A


-------------------------------------------------------------------------------
Address 02: Auto Trans Labels: 01V-927-156.lbl
Part No: 4D0 927 156 L
Component: AG5 01V 3.7lV8 RdW D74
Coding: 00000
Shop #: WSC 00000
VCID: 3265E53AD4BF

1 Fault Found:
18265 - Load Signal: Error Message from ECU
P1857 - 35-00 - -

End ---------------------------------------------------------------------


Thanks.

silverd2

I would do a very thorough inspection for vacuum leaks...all hoses, intake tube fittings, etc....code P0102 can be just as likely a leak, allowing unmetered air, as an actual MAF problem...I would suspect this 1st with a new MAF in place.

At 100K miles, it's time for new front 02 sensors anyway. Don't waste money on plug-n-plays...more $$ than they're worth. Bosch universals are exactly the same sensor as OEM, way cheaper and easy to wire into existing plug.

midnightgolfer

That sounds a little bit too much like actual work ;-P - but, I'll get back on finding those leaks.

Excellent insight. Do you have any recommendation as to where to purchase them?

Thanks again.

silverd2

[QUOTE=midnightgolfer;24150677
Excellent insight. Do you have any recommendation as to where to purchase them?
Thanks again.[/QUOTE]

I assume you're outside the U.S. ? The guys I buy from don't ship internationally: http://www.partsgeek.com/ Best prices on brand name stuff, fastest shipping...I buy anything I can from em...never a problem.

If you're in the UK, I found this place with reasonable prices...don't know if it's the best source(?):
http://www.eurocarparts.com/ecp/c/Au...a7cf033c6&LAMS

midnightgolfer

It has taken me a year, and after trying a new MAF sensor, I have accomplished the following...
Replaced intake manifold bolts, repaired a stripped thread-hole, replaced the intake gaskets, throttle-body gasket, injector o-rings, all breather hoses with their actual OEM Audi hoses, (one across the front, three in the rear,) the tube that goes to the brake booster (OEM,) the throttle-body boot (OEM,) replaced the all the small-diameter hoses with standard tubing of identical diameter, thoroughly cleaned the check valve and vacuum check valve and suction pump complex, checked the vacuum reservoir bottle, the manifold change-over bellows/actuator, replaced the air filter and the spark plugs (with actual Bosch/VW/Audi Platinum+4 that are supposed to be in the engine,) replaced an iffy spark controller-amplifier (got rid of random misfires in bank one,) the valve-timing hall-sensor (did nothing,) put in new O2 lambda sensors, and cleaned the throttle-body butterfly valves. And looked in the box where the ECU and TCU live to see if it looks like any water got in there. (It doesn't.) And, I drove it around for about 100km to see if the ECU has to "learn" anything.

I still get the same MAF, O2 and tranny error codes, and the tranny still won't do Tiptronic anymore, just normal auto-mode, (Not Limp Mode.)
16486 - Mass Air Flow Sensor (G70): Signal too Low
P0102 - 35-00 - -
16518 - Oxygen (Lambda) Sensor B1 S1: No Activity
P0134 - 35-10 - - - Intermittent
16538 - Oxygen (Lambda) Sensor B2 S1: No Activity
P0154 - 35-10 - - - Intermittent
17541 - Oxygen (Lambda) Sensor Heating; B1&B2 S1; Heating Circuit: Elect. Malfunction
P1133 - 35-00 - -
18265 - Load Signal: Error Message from ECU
P1857 - 35-00 - -

**Before I try yet another new MAF sensor, just to see if I got a bad one a year ago, am I missing anything?

midnightgolfer

In VCDS Vag-com, after replacing something like MAF sensor or O2 lambda sensors, is it necessary to do more than just erase DTC to reset, or is some sort of adaptation also necessary?

If so, how does one perform this adaptation?

Thanks.

silverd2

Nope...erase only...plug-n-play. I've changed both myself.

Just a guess, but from those codes (esp if components were replaced) you may have an ECM problem...or connection, wiring, etc...

midnightgolfer

I've been saving and working at this for all this time, just hoping that it isn't electronic / computer related. The only shop anywhere around me that I trust to try and determine it from this point, sadly, is the stealership.

And by "trust" I mean, they will get to the correct solution, after charging a ridiculous amount for diagnosis, and an even more ridiculous amount for parts.

Anybody know a trustworthy automotive electrician in Madrid?

midnightgolfer

P.S. It seems to have a real-world effect, as well. I just took it to see if I could get it to pass the smog inspection and it has extremely high carbon monoxide levels. Running rich?

silverd2

Well, if you are getting "no activity" from the front 02
sensors (as your codes say), then fuel is not being mixed properly with air...maybe running on a default setting, which would likely be rich. I know my (and others) mpg's improved a little with new sensors.
I'm not sure if a rich condition would produce higher CO level, though....possibly(?)