BinsuJiro

IM SORRY; IT IS A LONG STORY, and I'm compulsive about detail!

I've purchased a number of Audi vehicles via CarTrader.com and have always done very well with the Audi 100, and two A6 quattro Avants I bought.

But, I got suckered on a recent purchase for my son in PA. I brought my laptop and my Ross VAG.COM and ran all of the tests. There was only a slight fluctuation in the Secondary Air system test, but no sign of any other problem relative to noise, smell, drivability or by visual check.

The seller took great pains to indicate multiple times that the car passed PennDOT inspection with flying colors, but after getting the car back to NY, we started to have some serious problems. Within several days the smell of oil/exhaust fumes started to be noticed; in a few more days the exhaust became very noisy, and a few days after that the noise could wake the dead.

I didn't check this at the time of purchase because there were no indicators, but I got the car up on jack stands and was shocked to see that the Flex Joints were completely severed from the header pipes. I know damn well that this does not happen over night, and have dealt with this problem several times before, and it took months to get to this state. I also noted new clamps and nuts and bolts further down the exhaust pipes.

I surmise that the cats were removed (Monroe County PA) and were replaced prior to sale by just jamming the ends of the flex joints into the ends of the header pipes, and clamping the pipe as far forward as possible. The PA inspection station had to have forged the inspection report. PennDOT is filing criminal charges against the station.

Yesterday, I had new flex joints welded on, but nothing we could do could get the car to pass NYS inspection. Test results show error codes, but they fluctuate widely, but the following error codes persisted:

Address 01: Engine Labels: 078-907-551-AHA.lbl
Control Module Part Number: 4D0 907 551 AH
Component and/or Version: 2.8L V6/5V MOTR AT D04
Software Coding: 06251
Work Shop Code: WSC 06335
VCID: 6CDC0F001C1C1778EDD
2 Faults Found:

16486 - Mass Air Flow Sensor (G70)
P0102 - 35-00 - Signal too Low
18032 - MIL Request Signal Active (Check TCM for errors too!)
P1624 - 35-00 -

And the vehicle would not pass the readiness tests:

Readiness Status: 0010 1101
Exhaust Gas Recirculation: Passed
Oxygen Sensor Heating: Passed
Oxygen Sensor(s): Failed or Incomplete
Air Conditioning: Passed
Seconday Air Injection: Failed or Incomplete
Evaporative Emissions: Failed or Incomplete
Catalyst Heating: Passed
Catalytic Converter(s): Failed or Incomplete

I would start with the two persistent error codes, but there also seem to be serious problems with the cats and O2 sensors.

I really just want to get this vehicle back to the seller and to that end will be filing against him in Monroe County, PA, but in the mean time I want my son to be able to get to work and I don't want to spend a fortune on this troubled vehicle.

Any and all advise is welcome, and I thank anyone willing to attack this problem in advance.

Best regards,
Binsu

AudiMick

How does the vehicle drive?

The readiness codes will take some time to set, you normally need several complete cycles from cold before readiness will occur.

Try cleaning the MAF with alcohol or replace it. Check to see if when you remove the oil cap with the motor running there is excess pressure because the PCV system is blocked up.

BinsuJiro

(Should I reply above or below the quote?) For now I'll do it below.

The vehicle drives great in reverse, but is very sluggish in forward motion; it will eventually get up to a speed consistent with local traffic. I will check the MAF and PCV system, and retry the readiness tests again.

The biggest problem is a teenager who sees the car there and wants to use it and will not use one of the A6 Avants because they are not cool, and besides teenagers don't see past the next minute.

Is there a concrete consequence to running the A4 in LIMP mode that I can tell him about?

HJB

Vagcom allows you to reset readiness codes to all zeroes (at least for my DBC 1.8T). I don't believe there is a "limp" mode for DBC, only the DBW engine codes that have a MAP. Also did you try cleaning/replacing the MAF?

BinsuJiro

MAF is on the list of things to do tomorrow, but could you help with the abbreviations, DBC, DBW, MAP.

Thank,
Binsu

HJB

DBC - Drive by cable
DBW - Drive by wire
MAP - Mass air pressure