2009 chevy express 2500 code p0171
December 13th, 2023, 4:24 PM
#12
P0171/P0174 - Are there any leaks at the exhaust manifolds? If so, those need to be repaired before pursuing other possible causes of these codes. The leaks will allow excessive oxygen into the exhaust stream and skew the sensor readings.
Low fuel pressure is another possible cause. Spec is 50-60 PSI at the rail - should hold for at least a few minutes at KOEO and maintain it KOER at idle. The regulator is part of the fuel pump assembly in the tank.
P0121 - clean the throttle body bore, if necessary. Carbon accumulation around the throttle plate can cause it to stick/drag/bind and intermittent stalling and/or idle concerns can result.
If the TB is clean, monitor the TPS signal KOEO and slowly press the accelerator pedal all the way to the floor and slowly release. Watch for sudden changes in the signal that aren’t the result of your movements. Any sudden changes indicate the throttle body requires replacement.
Low fuel pressure is another possible cause. Spec is 50-60 PSI at the rail - should hold for at least a few minutes at KOEO and maintain it KOER at idle. The regulator is part of the fuel pump assembly in the tank.
P0121 - clean the throttle body bore, if necessary. Carbon accumulation around the throttle plate can cause it to stick/drag/bind and intermittent stalling and/or idle concerns can result.
If the TB is clean, monitor the TPS signal KOEO and slowly press the accelerator pedal all the way to the floor and slowly release. Watch for sudden changes in the signal that aren’t the result of your movements. Any sudden changes indicate the throttle body requires replacement.
December 13th, 2023, 5:37 PM
#13
you won't . It's part of the pump.
What's going on with your van?
What's going on with your van?
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Triaged (December 13th, 2023)
December 13th, 2023, 5:40 PM
#14
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Idkchevy1234 (December 13th, 2023)
December 13th, 2023, 5:41 PM
#15
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Idkchevy1234 (December 13th, 2023)
December 13th, 2023, 6:13 PM
#17
December 13th, 2023, 6:16 PM
#19
that's "system lean" right?
Many possible causes for that.
It can be exhaust leaks, vacuum leaks, bad injectors, dirty MAF, misfiring, etc. etc.
Yes fuel is one possibility. So verify your fuel pressure with a gauge.
Don't go straight to the parts cannon.
Follow the troubleshooting steps here: https://www.obd-codes.com/p0171
Many possible causes for that.
It can be exhaust leaks, vacuum leaks, bad injectors, dirty MAF, misfiring, etc. etc.
Yes fuel is one possibility. So verify your fuel pressure with a gauge.
Don't go straight to the parts cannon.
Follow the troubleshooting steps here: https://www.obd-codes.com/p0171
December 13th, 2023, 6:24 PM
#20
that's "system lean" right?
Many possible causes for that.
It can be exhaust leaks, vacuum leaks, bad injectors, dirty MAF, misfiring, etc. etc.
Yes fuel is one possibility. So verify your fuel pressure with a gauge.
Don't go straight to the parts cannon.
Follow the troubleshooting steps here: https://www.obd-codes.com/p0171
Many possible causes for that.
It can be exhaust leaks, vacuum leaks, bad injectors, dirty MAF, misfiring, etc. etc.
Yes fuel is one possibility. So verify your fuel pressure with a gauge.
Don't go straight to the parts cannon.
Follow the troubleshooting steps here: https://www.obd-codes.com/p0171