The check engine light revealed a mass air flow and knock sensor failure on my 1997 pathfinder. I had just changed the spark plugs,timing belt, and air filter, could any of those things caused the problem?
maybe. depending on the mechanic he may have disturbed the mass air sensor wire when doing the cleaner replacement causing the code, the knock sensor may be somehow reacting to the mass air flow sensor. if the plugs are correct and installed right I would expect all to work fine on the knock sensor. but the knock sensor reads when a cylinder is missfiring or knocking for what ever reason. bad fuel does this as well