Now's a good time to clean those terminals anyway. Now store a new profile by driving the car a bit briskly in situations where the car has been pinging before. It should learn the new profile. Do this with a new tank of the gas you would prefer to run. That would be regular, I'd bet.
Second solution is a bit more drastic and expensive in the long run.
Upside is that the pinging will almost assuredly be eliminated. Downside is that performance and economy will suffer if you do this. The octane shorting block is located under the hood, in a harness just to the rear of the fuse box. So if you are standing at the right front corner of the car with the hood open, move to the rear a bit to the fuse box. Now, look at the rear of that fuse box for a big bundle of wires that goes toward the firewall and somewhat down towards the engine.