P1132moderate severityPowertrain
HO2S Bank 1 Sensor 1 Air/Fuel Ratio Too Rich
on 2008 Mazda Mazda3 2.0L I4 · FWD
What this code means
The upstream heated oxygen sensor on Bank 1 indicates a persistent rich air-fuel ratio. The PCM fuel trim correction has reached its maximum lean limit but cannot correct the rich condition.
Symptoms
- Check Engine Light
- Rich exhaust smell
- Black exhaust smoke
- Poor fuel economy
- Fouled spark plugs
Common causes
- Leaking fuel injector
- High fuel pressure from faulty regulator
- Faulty O2 sensor reading rich incorrectly
- EVAP purge valve stuck open
- Coolant entering combustion chamber
Diagnostic steps
- Monitor fuel trim values on scan tool
- Check fuel pressure with gauge
- Inspect spark plugs for rich fouling
- Test for leaking injectors
- Check EVAP purge valve operation
Repair notes
Correct the source of the rich condition; check fuel pressure, injectors, and the O2 sensor.
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