One problem related to engine exhaust system has been reported for the 2007 Mazda MAZDA3. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2007 Mazda MAZDA3 based on all problems reported for the 2007 MAZDA3.
The fiberglass tunnel heat shield had deteriorated and parts of the fiberglass were falling onto the exhaust piping and catalytic converter and burning. The odor from the burning was noticeable both inside the car and when standing outside next to the engine. Burning occurred both when the car was stationary and in motion.