Truck also spark knocking
I was experiencing moderate to severe spark knock recently. I checked down the TB and found no oil. It was clean except a light film which I thought would be normal from the fuel. The plenum gasket was changed at 29000 mi. It now has 79000 on it. I also checked for vaccum through the PCV valve, also ok. I re-routed the plug wires per the TSB. My last atttempt at finding the cause, I put a bottle of octane boost in and immediately the knock went away. I've been running mid-grade gas since and no knocking. Does this mean I need a program adjustment? New plugs, cap, wires, rotor were changed in early summer.