Possible causes – Lack of intake air volume (block air filter)– Fuel injection system (Clogged fuel injector or bad fuel pump)– Faulty Engine Control Module (ECM) Tech notes There is a factory service bulletin for the following Nissan models: 2007-2009
Possible causes – Lack of intake air volume (block air filter)– Fuel injection system (Clogged fuel injector or bad fuel pump)– Faulty Engine Control Module (ECM) When is the code detected? The P1421 code is detected when The Engine Control
Symptoms – Engine Light ON (or Service Engine Soon Warning Light) P1421 Information for specific makes P1421 BUICKP1421 CADILLACP1421 CHEVROLETP1421 GMCP1421 NISSANP1421 INFINITI
P1421 CADILLAC – Intake Air Low Pressure Switch Circuit High Voltage
P1421 CHEVROLET – Intake Air Low Pressure Switch Circuit High Voltage
P1421 GMC – Intake Air Low Pressure Switch Circuit High Voltage
P1421 BUICK – Intake Air Low Pressure Switch Circuit High Voltage