P0332 is knock sensor low voltage. Not likely your problem why it won’t run. New Knock sensors and wiring harness (GM oe parts only) usually solve this.
P1516 is the electric throttle actuator on the throttle body. For this I’d first check the connector to make sure it’s got clean contacts and the wiring looks in tact. Next I’d pull the air intake boot off the throttle body and check to make sure that there’s not a bunch of carbon or gummy buildup at the opening where the butterfly flap is. This is controlled with the throttle actuator so if it’s gummed up or gets carbon stuck in there it can cause that code.
Throttle actuator is where the hand is in this pic. The gold colored piece is the parts to keep clean and the areas surrounding it.
Now as I think about the fact that these two codes are both current and the close proximity to both I can’t ignore checking to make sure they don’t share a common ground. Might be worth tracing the wiring for the throttle actuator and checking for signs of chaffing or rodent activity or corrosion. All are possible. Just depends on how the vehicle is treated, stored, and which region you live in, etc.
