Possible Causes
WARNING: This page is about a different car, the 2003 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.
Possible causes are:
- Front HO2S deterioration
- Front HO2S heater malfunction
- Fuel pump malfunction
- Fuel return hose clogged
- Misfire
- PCV valve malfunction
- Pressure regulator malfunction
- Purge solenoid hoses - improper connection
- Purge solenoid valve malfunction