I bought my infiniti with 109K on it. Now it has 112,000 miles. My car was pinging right after I bought it. The sound was coming from the engine and it got louder and louder in hot weather. I took it to a couple of mechanics who plugged it into a computer that said everything was working the way it should be. I am using the highest octane gas from Chevron and Shell, but it's not making any difference. I used big named fuel system cleaners but it didn't help. It has the same engine as Maxima 2000- 2003. Do you have any idea how to get the pinging to stop?
It is possible that your ignition system could be causing this issue. The combustion of fuel is a two part process: the introduction of fuel and the ignition of fuel. Everything you have done to resolve this issue has been related to the fuel system. After all that service has been done, it is unlikely that the fuel system is causing this issue.
I would recommend having your spark plugs and ignition coils checked for proper function. If your spark plugs are fouled out this may also cause your engine to ping. Have a certified mechanic performs these checks for you and diagnose the pinging from your engine.