Error code P0171 on an '04 Chevy Cavalier. Fuel system lean on bank 1.?

Jimmy Mills

New member
Joined
Jan 21, 2010
Messages
1
Reaction score
0
Points
0
I realize that this is probably a problem with an O2 sensor, but apparently there is a bank 1 sensor 1, bank 1 sensor 2, bank 2 sensor 1, and bank 2 sensor 2. I can only find one O2 sensor on my entire exhaust pipe, how do I know which one of these sensors that is and which of the two bank 1 sensors is the problem?
 

autojoe

New member
Joined
Dec 14, 2009
Messages
10
Reaction score
0
Points
0
Age
61
bank 1 sensor one is always located on the bank that cylinder one is located.you also have pre and postcat 02 sensors.your code related to a condition that affects bank 1 the side that cylinder 1 is located on.most of the time it is not the 02 sensor......it is a condition that affects bank 1.could be a vacuum leak.does the engine run rough or hard start?do you have a dc voltmeter?
 

autojoe

New member
Joined
Dec 14, 2009
Messages
10
Reaction score
0
Points
0
Age
61
I researched and should have a 4 cylinder engine......you should only have 2 02 sensors a pre cat and a post cat 02 sensor.the pre cat 02 is responsible for fuel trim calculations.it is located before the catalytic converter in the exhaust manifold.since you have only a bank 1 sensor 1 02 then the lean condition affects the whole engine which would include the following items:
Air leaks in intake manifold, exhaust pipes or exhaust manifold
Fuel control sensor is out of calibration (ECT, IAT or MAP)
Low fuel pressure (fuel filter clogged, pressure regulator failure)
One or more injectors restricted or pressure regulator has failed
HO2S element is contaminated, deteriorated or has failed
Vacuum hose is disconnected, broken, leaking or loose.would need to hook a dc voltmeter to the pre cat 02 signal wire and see what it is doing.a dso scope is what I use which most do not.
 
G

G-328500

I found this on here and having the same issue I replaced bank1 and bank 2 02 sensors today checked the fuel pressure regulator and all the vacuum lines nothing help plz.
 

zora

Staff member
Joined
Apr 24, 2012
Messages
4,315
Reaction score
57
Points
48
I found this on here and having the same issue I replaced bank1 and bank 2 02 sensors today checked the fuel pressure regulator and all the vacuum lines nothing help plz.
Do you have a 2004 Cavalier with a 2.2?
If so you dont have two rows of cylinders.
What year, engine, and code do you have?
 
Top