I have 2013 caprice L77 engine equipped with VCM cold air intake and XFORCE 1.3.4 headers . when i increase the timing one degree it shows lot of knocking , then decrease it one degree the scanner shows no knocking at all !!!
I attached the datalog .
kindly can anyone give an idea about what can cause these strange knocks ?
i tried :
1) increase octane
2) new spark plugs with new wires
3) desensitize knock sensor level