multiple error codes p0134 p0154 p0327 p0332

[Squid 308]

gday all im having some rather frustrating issues with my vts2 ss ls1 I used to get random 02 codes and would replace sensors every couple of years but slowly got worse and was throwing knock sensor codes (also would get pinning) the codes are p0134 p0154 p0327 p0332 ive replaced both 02 sensors with bosch sensors and replaced the knock sensors with genuine holden ones and replaced the loom, still no good, hoping someone elese has come across this and has a fix, originally had factory manifolds with red back cat back system but now has pacemaker extractors with custom stainless 3" twin system (cat delete) I find it hard to believe all 4 sensors are bad.
any help appreciated