2008 5.3 Strange Spark Knock

[Chief121]

2008 Silverado 5.3. Just put in brand new AcDelco Iridiums this morning. Noticed in log I'm getting really erratic spark advance movement compared to TPS. Also don't know how legit the knock retard is. Have a feeling its false knock but not too sure. Running 87 Octane. I have subtracted knock retard amounts from both Octane tables but it continues to show knock leading me to believe its false. What percent can I safely desensitize my knock sensors in hopes that they are just being sensitive. Also noticed that cyl 5 is consistently knocking 1.5* more than all the other cylinders. Any reason for that?

NewPlugs2.hpl

[kevin87turbot]

Try 93 octane and see if it goes away. Also check out this thread...https://forum.hptuners.com/showthrea...-when-cruising