I am new to data logging and am trying to chase down high knock counts on my 95 K2500 5.7 TBI all stock. It starts, idles and runs very well. I was surprised to see very high knock counts (over 10,000 after 20 min). Changed to cooler plug and tried 92 instead of 87 octane both with no change what so ever.

Happens on acceleration and mellow cruise 1600-2000 rpm. One question I have (other than what clues I can look for to pin point which of all the things that can cause knock this might be?) is the the Desired AFR never goes above 14.2 and seems to average 13.5 to 14 throughout the drive on mellow country roads. Is this normal or a clue to a problem? I guess I was expecting it to fluctuate more.

Any advice appreciated!