Audible Knock Retard 2007 Escalade

[wa04compg]

Noticed recently wife's stock 2007 Escalade 6.2 has audible knock WOT. Hooked up scanner and is seeing up to 7* of KR WOT. She has always ran 92 octane and have not noticed audible knock before. I put fresh tank of 92 KR numbers went down a little but still could hear it knocking. Noticed it is only doing .65 cyl airmass at WOT and MAF o2 sensor appear to be working fine. The stock tune at .65 airmass between base table and adder tables is shooting for 25*+ of timing at WOT. Based on my cam header G8 liking 23* this seems odd to me. I backed off adders to max WOT timing at 20* and KR on scanner went away and also no audible knock. Friend of mine scanned his stock 2011 denali 6.2 and is seeing .78 airmass where i am seeing .65 and had 23* timing no KR issues at all. Is there any chance because of different ECM/MAF setups between 2007 and 2011 that my 07 would be ready lower airmass or is there something wrong with mine. If it is normal I find it crazy that GM would be asking for 25-30* of WOT in a full size suv depending on adders. Anyone have any thought on this?2007 Escalade Esv Stock Tune.hpt

[pdsq98gt]

Does the truck still have cats? If so your cats could be restricted and causing these issues. It would explain the lower airflow and it?ll cause knock.

[cadillactech]

Cats could be the issue but I have seen carbon build up in the combustion chamber cause knock on many 6.2Ls
Also if your PCV system is sucking oil into the intake, your 92 octane is now 87 octane or worse. The PCV systems can get clogged up pretty bad on high mileage ones, there is updated valve covers to reduce oil pulling into the intake.
Trying doing an engine decarbon and then seeing if knock is less.