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.
- EGR boost sensor malfunction.
- EGR boost sensor solenoid valve malfunction.
- Loose, damaged, misrouted or plugged vacuum hoses between EGR boost sensor and EGR boost sensor solenoid valve or between EGR valve and EGR boost sensor solenoid valve.
- PCM malfunction.