1998 Mazda Protege EGR Valve

Suggested Repair

Remove the intake manifold and clean carbon from all EGR ports, especially the port to the EGR boost sensor. Aerosol intake cleaners will not clear these ports. The EGR valve itself may be fine.

Conversation Summary

The owner of a 1998 Mazda Protege LX 1.5L with 133,000 miles has a check engine light and was told the EGR valve and catalytic converter were failing. They asked if the EGR valve could be cleaned instead of replaced. A Mazda technician said the valve is often fine and the usual problem is carbon clogging the EGR port to the EGR boost sensor, which requires removing the intake and cleaning the EGR ports. Canned intake cleaners will not clear those ports.