After my car has warmed up for a while and I accelerate kinda hard I hear this loud pinging noise that almost sounds like a diesel and then my check engine light will come on. I checked the codes and I got 42 and 43 which have to do with the EST. As soon as the light comes on the knocking stops. My friends dad said that my knock sensor could have gone bad. Where is this located and how hard is it to replace?

 

The sensor itself is located on the passenger side of the block, screwed into the water jacket drain hole. It's not hard to replace, need to do it from underneath, just be ready to catch some coolant.