Possible Causes
WARNING: This page is about a different car, the 2003 Mazda Protege5 and 2003 Mazda Protege. However, it is still accessible from the selected car via links, so may be relevant.
- Warm-up Three Way Catalytic (WU-TWC) converter deterioration or malfunction.
- Exhaust system leak.
- Loose rear HO2S.
- Loose front HO2S.
- Front HO2S malfunction.