Posts Tagged: P0421 Mazda

P0421 Mazda

P0421 Mazda — Diagnose and Fix Mazda has issued a service bulletin #01-010/16 for the vehicles listed below to address a P0421 Mazda trouble code issue. The bulletin reports that some vehicles may have a check engine light along with trouble code PO421:00 (Catalytic converter system) without experiencing poor engine performance or misfire. Mazda has determined that the ECM software is incorrectly commanding the air/fuel sensor which results in a false PO421 Warm up catalyst system efficiency below threshold. Mazda has issued a software update to correct the problem. The … Read More