The exhaust recirculation valve (EGR) on the 2002-2017 Acura MDX may fail, causing:

  • Illumination of the check engine light
  • OBD trouble codes P0401and P1491
  • Rough idle
  • Reduced fuel economy
  • Engine vibrations
  • Hesitation or stalling
  • Long cranking before engine starts
  • Failure of state or federal smog tests

The EGR valve has open and closed positions, and opens or closes on command from the computer.

Exhaust gases constantly pass through the valve when it is open, leaving carbon deposits on the valve. These carbon deposits may lead the the valve sticking in the open or closed position.

To correct this issue, sometimes it is sufficient to clean the valve, but replacement is recommended in all cases.

For further information on your vehicle's issue, try out our diagnostics tool here.