Help: P0171 System too Lean (Bank 1)
#1
Help: P0171 System too Lean (Bank 1)
Anyone familiar with what this error could point to on an '02 3.8L? P0171 System too Lean (Bank 1) I assume something to do with not getting enough gas. This is the first time this SES showed up, and when reset it has not returned...
TIA!
TIA!
#2
How far have you driven it since the reset? I would assume that the problem is fixed somehow if youve gone more than 20 miles or so (sometimes 60 miles for the computer to fully cycle through). perhaps there was some gunk in the injector or the o2 sensor was giving a false reading to the computer.
#3
LOL zero, it's at the dealer getting fixed for other problems, but they could not get the code to come back after reset and found nothing wrong... Guess I will see how it goes over then next 3k miles...
How far have you driven it since the reset? I would assume that the problem is fixed somehow if youve gone more than 20 miles or so (sometimes 60 miles for the computer to fully cycle through). perhaps there was some gunk in the injector or the o2 sensor was giving a false reading to the computer.
#4
I had a bunch of codes on one of my other cars. I reset them and it was fine. I drove for 30 miles or so and it started acting a fool. No ses lights but the codes returned. Thing is while is sat and idled there was nothing wrong, it needed a load to hit the code.
#5
I wonder if in my case it has anything to do with the SLP CAI & Whisper lid -- i.e. more airflow, and perhaps the computer isn't readjusting the air/fuel ratio adequately - as if a tune is needed?
#6
I dont have alot of experiance with the newer stuff, but would assume thats exactly th eproblem. Ali or Pete would know for sure ( as would other members, they are just tth etwo I can think of off the top of my head)
#7
Hey Pete & Ali -- what sayeth you? ;-)
#9
No, actually it seemed to be running normal.
The only thing I know I need to replace is the serpentine belt due to a thumping sound (the belt is fraying)... But I doubt it's related.
I have been using some Lucas Fuel System Cleaner lately -- I wonder if it somehow dislodged some debris that temporarily got stuck somewhere like an injector but cleared itself?
The only thing I know I need to replace is the serpentine belt due to a thumping sound (the belt is fraying)... But I doubt it's related.
I have been using some Lucas Fuel System Cleaner lately -- I wonder if it somehow dislodged some debris that temporarily got stuck somewhere like an injector but cleared itself?
#10
If the codes don't come back, I wouldn't worry about it. One thing I noticed on some OBDII cars is that they will throw lean codes if the intake is messed with (Monte Carlo SS comes to mind).
Anyway, according to All Data:
DTC P0171:
CIRCUIT DESCRIPTION
The powertrain control module (PCM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy and emission control. Fuel delivery is controlled differently during Open and Closed Loop. During Open Loop the PCM determines fuel delivery based on sensor signals, without oxygen sensor input. During Closed Loop the PCM adds oxygen sensor inputs to calculate Short and Long
Term fuel trim, fuel delivery adjustments. If the oxygen sensors indicate a lean
condition, fuel trim values will be above 0 percent . If the oxygen sensors (O2S) indicate a rich condition, fuel trim values will be below 0 percent . Short Term fuel trim values change rapidly in response to the heated oxygen sensor (HO2S) voltage signals. Long Term fuel trim makes coarse adjustments in order to maintain an air/fuel ratio of 14.7:1. If the PCM detects an excessively lean condition, this diagnostic trouble code (DTC) will set.
DIAGNOSTIC AIDS
* The system will go lean if an injector is not suppling enough fuel.
* A lean condition could be present during high fuel demand due to a fuel pump that does not pump enough fuel.
* Using a scan tool, review the Failure Records. If an intermittent condition is suspected, refer to Intermittent Conditions. See: Symptom Related Diagnostic
Anyway, according to All Data:
DTC P0171:
CIRCUIT DESCRIPTION
The powertrain control module (PCM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy and emission control. Fuel delivery is controlled differently during Open and Closed Loop. During Open Loop the PCM determines fuel delivery based on sensor signals, without oxygen sensor input. During Closed Loop the PCM adds oxygen sensor inputs to calculate Short and Long
Term fuel trim, fuel delivery adjustments. If the oxygen sensors indicate a lean
condition, fuel trim values will be above 0 percent . If the oxygen sensors (O2S) indicate a rich condition, fuel trim values will be below 0 percent . Short Term fuel trim values change rapidly in response to the heated oxygen sensor (HO2S) voltage signals. Long Term fuel trim makes coarse adjustments in order to maintain an air/fuel ratio of 14.7:1. If the PCM detects an excessively lean condition, this diagnostic trouble code (DTC) will set.
DIAGNOSTIC AIDS
* The system will go lean if an injector is not suppling enough fuel.
* A lean condition could be present during high fuel demand due to a fuel pump that does not pump enough fuel.
* Using a scan tool, review the Failure Records. If an intermittent condition is suspected, refer to Intermittent Conditions. See: Symptom Related Diagnostic