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:

Following oil runners are clogged or have leakage:
1. Between oil pressure switch and right side OCV
2. Between right side OCV and right side variable valve timing actuator
3. In right side variable valve timing actuator
Loose timing chain or improper valve timing
Low engine oil pressure
PCM malfunction
Right side variable valve timing actuator is stuck in retard position
Spool valve in right side Oil Control Valve (OCV) is stuck in retard position