We have an 02 SE/SC. It has a bad knock sensor I think. I remember reading something about checking the bypass valve at idle to see if it is stuck open. When the truck is idling the plunger is down and the SC is rackety. If I push the plunger up it quiets down. Is this the test? Should the plunger be "open" when at idle? Or should it be closed like I am doing it manually?
Thanks!