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:
- Exhaust gas leakage
- Front HO2S malfunction
- Looseness of front HO2S
- Looseness of rear HO2S
- Three-Way Catalytic Converter (TWC) deterioration or malfunction