P1171moderate severityPowertrain
Fuel System Lean During Acceleration
on 2002 Cadillac Escalade 6.0L V8 · 4WD
What this code means
The PCM detected that during power enrichment mode (heavy acceleration in closed loop), the expected rich condition was not detected by the O2 sensors. This means the fuel system cannot supply adequate fuel during hard acceleration. A plugged fuel filter or restricted fuel line is a common cause.
Symptoms
- Check Engine Light
- Hesitation or stumble during hard acceleration
- Loss of power under load
- Poor fuel economy
- Engine misfires under load
Common causes
- Clogged fuel filter
- Weak or failing fuel pump
- Restricted fuel line
- Faulty oxygen sensor
- Vacuum leak
- Contaminated or clogged fuel injectors
- Dirty MAF sensor
Diagnostic steps
- Test fuel pressure at idle and under load
- Replace fuel filter
- Inspect fuel injectors
- Check for vacuum leaks
- Clean or test MAF sensor
- Monitor long-term fuel trim values
Repair notes
Replace fuel filter and test fuel pump pressure/volume. If fuel delivery is adequate, check for vacuum leaks and dirty injectors.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1