Hey all, I am new at this. I have a 02 Maxima (37K) and it started knocking/pinging regardless of type of Gas used. It's Very loud on a slight uphill. Any insight on this???

Change your MAF sensor.

Take your car to autozone... look for codes, if engine cylinder misfire, then may be a bad ignition coil... maxima's known for this. I replaced one (after replacing O2 sensors x2, and knock sensor)... low and behold the ingnition coil did the trick!

Cost from autoparts 911 was $78

I have the same issue as well, accept mine is more mild.... can it be the valves?

MAF? isnt that more intake related njmaxseltd? its either blown or not i believe.....

also, how does the knock/02 sensor work and what affects their operation?