What would cause 1 or 2 cylinders to knock, but not others?

[tryingbe]

My OTC scan tools says I'm pulling timing on #2 and sometimes #3 cylinder. Other than plugs and injectors, would there be other reasons?

Working on getting the parts so I can log the data from the scan tool.

[RoadWarrior222]

First thing I'd try is a compression check.

[supercrackerbox]

Carbon buildup.

[shadow88]

The knock sensor is closest to #2 and 3, so that's part of an easy answer. Maybe it's a noisey lifter or rocker arm that the sensor picks up?

[Shadowv4l]

center of the head/block, getting hot?