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P1491 on the 2002 Acura MDX

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.

This code is specific to a manufacturer and is not described here. Its meaning is in the manufacturer's service information.

Bulletins for this model year that name P1491
05-0192008-04-24. Service bulletin. ACURA SERVICE CAMPAIGN: SEE DOCUMENT SEARCH BUTTON FOR OWNER LETTER. WARRANTY EXTENSION: EGR VALVE CONTAMINATION MAY CAUSE ENGINE HESITATION/SURGE OR DTC P1491. CSC WAS RECEIVED. *NJ

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.