P0171 system too lean bank 1
Thread Starter
Joined: Jan 2006
Posts: 12
Likes: 0
P0171 system too lean bank 1
My check engine light is on. Ugh [>:] The code is number P0171 says that the systems is lean in bank 1. What does this mean and how do I fix it? Heard that it might be an O2 sensor but which one, how do I tell? Don't want to buy both or buy the wrong one. Yes the cat is off but it has ran fine without it and no check engine light for 8 months now. So I don't think its that. The truck will idle real rough. down real low then up high back and forth. Sometimes just has no power at all. HAD TO PUT IT LOW RANGE TO TAKE OFF ONE TIME SO I DIDN'T SLIP THE CLUTCH THAT BAD!! If u let any pressure off the accelerator, not completely let off, just release a little it will jump it surge. What is wrong with my truck? Any help please. Seriously thinking about going for a new crew cab duramax. 
Champion
Joined: Dec 2003
Posts: 4,119
Likes: 5
From: Sycamore, Illinois (displaced to Arkansas)
RE: P0171 system too lean bank 1
Bad oxygen sensors should throw differant codes (P0130 to P0167), so I would take the guess and say its not the sensors (but I can't say for sure). As I understand it, the upstream oxygen sensors tell the computer to richen or lean out the fuel, the downstream tell the computer if the catalytic converter is good.
Oxygen Sensors:
Bank 1 Sensor 1 - Upstream Left
Bank 1 Sensor 2 - Downstream Left
Bank 2 Sensor 1 - Upstream Right
Bank 2 Sensor 2 - Downstream Right
As I said in the other post: don't. In a word: Cummins.
Oxygen Sensors:
Bank 1 Sensor 1 - Upstream Left
Bank 1 Sensor 2 - Downstream Left
Bank 2 Sensor 1 - Upstream Right
Bank 2 Sensor 2 - Downstream Right
Seriously thinking about going for a new crew cab duramax.
Administrator
Joined: Apr 2010
Posts: 87,482
Likes: 4,223
From: Clayton MI
What's with folks not looking at posting dates? This thread is four years old, the OP has 12 posts, and hasn't been seen since july of '06. Seems logical to assume you are NOT going to get an answer from him......
Start your own thread. Post your vehicle and problem.
Threadomancy should be illegal.....
Start your own thread. Post your vehicle and problem.
Threadomancy should be illegal.....
Professional
Joined: Feb 2010
Posts: 192
Likes: 0
From: Texas
Welcome to the forum young1014. I would start a new post and tell us about your situation.
Heyyou--Give him a break, at least he did a search instead of jumping in with new post that's been answered a 1000 times.
Heyyou--Give him a break, at least he did a search instead of jumping in with new post that's been answered a 1000 times.