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 filter clogged or restricted
- Fuel leakage on fuel line from fuel delivery pipe and fuel pump
- Fuel pump malfunction
- Fuel return hose clogged
- Insufficient compression
- Leakage exhaust system
- Misfire
- Pressure regulator malfunction
- Purge solenoid hoses improper connection
- Purge solenoid valve malfunction
- Variable valve timing control system improper operation