P1136 & P1138 System Too Lean (Add)
 

2004 Audi A8L
4.2L V8

I hope someone could shed some light on these lean codes, I tried almost everything and they always come back.

17544 - Fuel Trim: Bank 1 (Add)
P1136 - 001 - System too Lean - MIL ON
17546 - Fuel Trim: Bank 2 (Add)
P1138 - 001 - System too Lean - MIL ON
17519 - Oxygen (Lambda) Sensor Regulation: Bank 1

THINGS I'VE DONE:
*Checked for vacuum leaks, couldn't find any. Also, when the car is warmed up, I never see the Lambda lean at idle so I'm not sure why the codes show lean(add). Maybe the fuel control in the ECU is faulty or the injectors are acting wacky?

NEW MAF
NEW Fuel Filter
NEW PCV Valve
NEW O2 Sensors
NEW Intake Manifold Gaskets
NEW Injector O-RIngs


************************************************** ******
MAYBE THIS IS THE RED FLAG?

Block 107 Always fails Basic Settings & the fuel goes to 25%, then I immediately get the following two codes after running the basic settings test. Thoughts?

17519 - Oxygen (Lambda) Sensor Regulation: Bank 1
P1111 - 001 - System too Lean
17555 - Oxygen (Lambda) Regulation Bank 2
P1147 - 001 - System too Lean

https://i7.photobucket.com/albums/y2...ps4e4a1968.png

The (Partial) in Block 032 is usually at least 8-10+% it's lower here because it's only a few miles after I reset the check engine light.

https://i7.photobucket.com/albums/y2...ps34084614.png

Any idea what could be causing this fuel addition only on the cold start once the temp hits ~40 degrees?
https://i7.photobucket.com/albums/y2...psbf1497bf.png

This log is from my other car, a 2006 A8L which has no check engine lights. As you can see, the fuel corrections are in the negative. So this could be the issue w/ the 2004 A8L.
https://i7.photobucket.com/albums/y2...ps8c4dc1ae.png

Unplugged MAF Test
 

MAF UNPLUGGED RESULTS
The MAF that was currently in this car was from my 2006 A8L that had no issues. Also note, the car ran exactly the same with the MAF unplugged because when I plugged it back in, the RPM and engine sounded the same.

***Air Fuel Lambda was on the rich side then the O2's corrected up to NEGATIVE 25%
***BLOCK 107 PASSED! Any ideas on what is causing this behavior?

https://i7.photobucket.com/albums/y2...pse99cf462.png

https://i7.photobucket.com/albums/y2...ps9fd94e63.png

https://i7.photobucket.com/albums/y2...psbd9ff751.png