So before i did this, the dealer had changed the sparkplugs to NGK iridium and cleaned the throttle body and intake.
That did NOT help.
So after that i used this bottle. Valvoline complete fuel system cleaner. It's the one that can be used after every 6000miles or 9600km.
I poured it in before filling up the tank to full, with premium gasoline.
I drove normally for two days with the pinging still present. Then after a drive, at home i played with my gas-peddle. In "P"position between 2000-3000 revolutions a few times bouncing after that between 4000-6000 revolutions somewhat 5 times bouncing with peddle. I let it idle and go to the limiter at 6500revolutions, gas-peddle fully pressed for only 2-3 seconds. I idle it for 30 seconds and turn it off.
The next day after warming up i start using hard acceleration 1-2 times in one run or in a day.
After only 3 days, the pinging disappeared.
That was my experience, with my nissan note and it may be different from everyone else. So please go to your mechanic first or use this carefully at your own risk.
Every engine may be dirty inside with carbon.
Change engine oil regularly.
But if it is too dirty, this will not help.
Your engine will have to be inspected or overhauled.
And check the EGR function also