P1421 FORD – Catalyst Damage

P1421 FORD Possible Symptoms

Engine Light ON (or Service Engine Soon Warning Light)

P1421 FORD Possible Causes

Faulty Catalyst,Catalyst harness is open or shorted,Catalyst circuit poor electrical connection

P1421 FORD Description

The Engine Control Module (ECM) monitors the Catalyst. The ECM sets the OBDII code when the Catalyst is not to factory specifications.