Possible Cause
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:
- Loose timing belt or improper valve timing due to timing belt slippage
- OCV malfunction
- PCM malfunction
- Spool valve in OCV is stuck in advance position
- Variable valve timing actuator is stuck in advance position