Well, I am not sure what my timing is at, but the engine rattles at random times. Mostly when I am excellerating, but not only then. I run it on regular 87, I have have tried a higher rated and that didn't help very much. I did buy the fuel system cleaner and that help a bit, but only while I used it. The knocking is coming from the engine though. Can't say where for sure because I only hear it while I am moving.
Try cleaning the MAF sensor. Chances are, you are pinging. Anyone with that problem needs to clean the MAF before moving on to fixes that actually cost money.