P0420 on the 1998 Dodge Ram
The bulletins listed name this code in NHTSA's summary, or are about the same components. A bulletin or a recall listed here may apply to the model year. None of it is a diagnosis.
Nobody has written a description of this code yet.
| 1100605 | 2006-01-27. Service bulletin. ILLUMINATED MIL AS THE RESULT OF A DIAGNOSTIC TROUBLE CODE (DTC) P0420 - CATALYST EFFICIENCY, OR MAY HAVE FAILED A CALIFORNIA SMOG OR STATE I/M TEST BUT WITHOUT AN ILLUMINATED MIL, OR A RATTLING SOUND FROM THE UNDERSIDE OF THE VEHICLE. CATALYTIC CONVERTER EXTENDED WARRANTY TO REPLACE THE CATALYTIC CONVERTER. *TT |
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1 on file from NHTSA, as of 2026-10-19. See them in the bulletin list. A bulletin lists model years: read the document for which vehicles it concerns.