knock issues 01 Suburban

[andysc3]

Hello, having some wierd knock on my suburban is someone can look at my log and tune that would be great.
2029520296

[joecar]

Did this just start happening...?

Possibilities:
- MAF is under-reporting.
- front NBO2 sensors are worn out.

[andysc3]

its been happening. so far Ive replaced the water pump, oil pump, timing chain, sparkplugs and wires, removed the intake manifold, completely cleaned it, reinstalled with new gaskets. I aslo have a new catted ypipe and o2 sensors just need to find the time to install them. I also noticed that my trims seem to be off. B1 will be around 4.5 and B2 will be around 2.