One problem related to catalytic convertor has been reported for the 2004 Toyota Matrix. The most recently reported issues are listed below.
The contact owns a 2004 Toyota Matrix. While driving approximately 35 mph, the vehicle failed to accelerate and the check engine warning light illuminated. The failure recurred multiple times. The vehicle was taken to an independent mechanic for diagnostic testing. The contact was informed that the catalytic converter needed to be replaced and the computer needed to be reset. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 150,000.