Gentlemen, chasing codes for 2 years now and can confidently say have exited the check engine light train.

H2 running super strong. Latest code was rear o2 sensors. P0141 and P0161. Checked fuses and they are good. Thermostat was pluged in. Turned out to be a loose sensor caused all the issues. Couple tips learned on the way.

I saved the original knock sensors. They looked super bad but still work. The ones with the green dot ended up breaking on me. Internals broke and caused false pinging. Dont use the ones from delphi they fail after 3 months. It snapped in the block. Used a 1/2 diehard socket removal tool came right out. Torque is 15lb. Always use gm harness. I prob had the go into knock sensors 6/7 times maybe more. Super annoying. 98 99 ohms are good