Thats what I am worried about..True pinging (pre-ignition) can ruin your engine if not resolved fairly quickly. I have seen it blow hole into pistons.
Good luck man, let us all know what you figure out.
I know it can't be a winter mix of gas, as I go through a tank a month and just had it filled a week ago. And the temp gauge was sitting right where it normally does.
I was planning on doing my plugs soon (and might as well replace the knock sensor while I am in there) but how would I check for a lean condition or look for its cause without a CEL?