dvs_dave

Glad you got it fixed, although sounds like you were confusing FSI engine diagnostics with older port type? Very different systems.

So it was the little diaphragm fuel pressure regulator that had failed? Do you have a photo of the failed part so others know what to look for?

tashakes

So I got the CEL on again last week. I am keeping this in this thread so it may help future searched.

CEL went out for about a day and went on again. Then went out for about 3-4 days and on again. I thought it was the cheap Pilot premium gas, but it came on again after about 1/4 into a new tank of Chevron premium.

Here are the codes I am getting

2007 A8L 4.2

Control Module Part Number: 4E1 910 560 A HW: 4E1 907 560
Component and/or Version: 4.2l V8/4V 0040
Software Coding: 01060009190F0120
Work Shop Code: WSC 02313 785 00200
VCID: 2044FBD1F3F7C042E9-8074

008569 - Bank 2; System Too Lean off Idle
P2179 - 001 - - Intermittent - MIL ON
Freeze Frame:
Fault Status: 10100001
Fault Priority: 0
Fault Frequency: 17
Reset counter: 255
Mileage: 121422 km
Time Indication: 0
Date: 2016.11.17
Time: 09:36:52
Freeze Frame:
RPM: 2228 /min
Load: 37.2 %
Speed: 120.0 km/h
Temperature: 94.0°C
Temperature: 35.0°C
Absolute Pres.: 1000.0 mbar
Voltage: 13.462 V

012555 - Low Pressure Fuel regulation
P310B - 004 - Fuel Pressure Outside Specification - Intermittent
Freeze Frame:
Fault Status: 00100100
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 121949 km
Time Indication: 0
Date: 2016.11.23
Time: 10:39:46
Freeze Frame:
RPM: 1260 /min
Load: 20.0 %
Speed: 31.0 km/h
Temperature: 100.0°C
Temperature: 48.0°C
Absolute Pres.: 1010.0

I did not change the G410 sensor as I did not have issues with CEL for over a year. Now I am thinking about it and also some injector cleaner in the gas.

Any other suggestions? TIA

aTOMic

1) Hate you guys because the 4.2L has no FP sensor. jelly. All those sensors and no measure of fuel pressure!?

2) The SSPs for the EVAP system are on the Bentley disc. It is relatively complicated, and I learned a LOT from it. TSBs, "Service Campaigns", and other surprising stuff is on there too. Use the search function and search several other words besides the sensor number you suspect.

3) The PCV / crankcase vent valve is a pretty delicate / sensitive / fragile part; I'd re-replace it/them - if I understand you correctly they fixed it the first time...

I'm no V12 (W12) expert, but they are so few and far between I thought I'd put in me tuppence. You may want to check the VW Vortex Phaeton forum; there are a lot of very polite, brilliant experts there (unlike the rest of VWV).

Tom

MP4.2+6.0

Injector cleaner (Techron) and maybe a fuel filter change. After that, basically down to prayers or fuel system repairs.

tashakes

Update: replaced G410. After 30 or so miles CEL back on. BUT..... I found when reading the TSB that I did not perform adaptation. So I did, and added injector cleaner to a fresh tank. So far 120 miles and no CEL. I hope the adaptation was what I was missing. Will come back later if I get another CEL.

Emmanuel Maldonado

Had the same code ran around crazy replacing both hpfp rear main pump low pressure fuel sensor. I end up putting fuel injector cleaner in the tank with only 5 bucks of gas and floored it on the highway. Parked it next day I did the same grabbed another fuel injector cleaner with 5 bucks of gas and floored it again. Cleared code and it never came back. I believe it was a dirty injector