Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P1421 Information for specific makes
P1421 BUICK
P1421 CADILLAC
P1421 CHEVROLET
P1421 GMC
P1421 NISSAN
P1421 INFINITI
P1421 CADILLAC
P1421 CHEVROLET
P1421 GMC
P1421 NISSAN
P1421 INFINITI