GM Service Manual Online
For 1990-2009 cars only

    Object Number: 309859  Size: SH
  1. Remove the knock sensor wire harness.

  2. Object Number: 309864  Size: SH
  3. Remove the knock sensors.

  4. Object Number: 668798  Size: SH
  5. Remove the valley cover bolts.
  6. Remove the valley cover and gasket.
  7. Discard the valley cover gasket.

  8. Object Number: 1272812  Size: SH
  9. Remove the knock sensor oil seals (520) from the cover (555).