Check Engine Light for Running Rough and Difficulty Starting on Honda Odyssey

Submitted by Vehicle Owner · May 29, 2025
Published by RepairPal

Problem overview

The exhaust recirculation valve (EGR) on the 1999-2016 Honda Odyssey V6 may fail, causing:

  • Illumination of thecheck 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.

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