P0174 - Fuel Trim; Bank2: system too lean - DTC fault....
Thread Starter
AudiWorld Member
Joined: Apr 2005
Posts: 538
Likes: 0
P0174 - Fuel Trim; Bank2: system too lean - DTC fault....
hey, got a CEL and pulled the codes with vag-com and got this:
P0174 - Fuel Trim; Bank2: system too lean
i did a search, and saw one person say it might be the MAF. anyone else get this recently and know what caused it?
P0174 - Fuel Trim; Bank2: system too lean
i did a search, and saw one person say it might be the MAF. anyone else get this recently and know what caused it?
AudiWorld Super User
Joined: Oct 2001
Posts: 15,311
Likes: 696
From: SF Bay Area, CA
Try...
If you have a 4.2, from experience seeing this code look at the vacuum lines that drive the secondary air injection. On my 2000 they are the ones under the center V trim cover that run along the cylinder head on the right hand side and then generally head behind the engine down toward the vacuum diaphrams. If you have never replaced your original German cloth braided hose (aka junk), it's only a matter of time before one piece after the next rots out, especially with the V8 heat. For me it started at about 2 years. After the third or so piece went I replaced it all--about 15 feet in total. No more problems.
Vacuum hose is easy and cheap to diagnose and replace. After that, my experience is to look at MAF next, particularly on the older ones where there is an extended warranty or if a KN oiled type filter has ever touched your car, which will likely poison the MAF in time.
Vacuum hose is easy and cheap to diagnose and replace. After that, my experience is to look at MAF next, particularly on the older ones where there is an extended warranty or if a KN oiled type filter has ever touched your car, which will likely poison the MAF in time.
Thread Starter
AudiWorld Member
Joined: Apr 2005
Posts: 538
Likes: 0
Re: Bentley says - You are correct!
awesome. u guys rock.. still 
so, since its the sensor, I wonder if the car is not actually running lean, but cause of the sensor, the computer *thinks* its running lean? (so i dont have to worry bought getting it fixed ASAP?..) altho **** it, with these gas prices.. ill leave it lean so itll use less gas :P j/k.. i know running lean is alot worse for a motor, than running rich.
geeez. car is too lean, and the bike is too rich.. i cant win :P
so, since its the sensor, I wonder if the car is not actually running lean, but cause of the sensor, the computer *thinks* its running lean? (so i dont have to worry bought getting it fixed ASAP?..) altho **** it, with these gas prices.. ill leave it lean so itll use less gas :P j/k.. i know running lean is alot worse for a motor, than running rich. geeez. car is too lean, and the bike is too rich.. i cant win :P
Thread
Thread Starter
Forum
Replies
Last Post
Uber Wagon 2.0
Rocky Mountain Discussion
3
May 26, 2005 01:30 PM
designmills4
S4 / RS4 (B5 Platform) Discussion
5
Aug 22, 2003 05:43 AM
ShoppingKartRacer
Audi 100 / A6 (C4 Platform)
13
Nov 21, 2002 06:26 AM
Kris Hansen
A4 (B5 Platform) Discussion
0
Sep 26, 2002 10:40 AM
Jeff Vader - boscoj
S4 / RS4 (B5 Platform) Discussion
1
Jan 26, 2002 12:06 PM
