Just decided to do some cruising around tonight and towards the end, I'm going through a small downtown area near me, got the car in 3rd and just giving it enough gas to keep the speedo the same. I look at my s-afc2 and knock is reading 60-70! So I pull in an empty gas station and give the engine a chance to cool down. I've never seen any knock issues except if I run my car for awhile, I'll let it sit and see between 0-6 at idle. Once I give it gas it goes away though. So it goes back to about a constant 7 in a few minutes, and I continue driving home and it pops back up out of nowhere! I give it some gas and it goes down to 2-7 or so. Never had these issues before, any ideas?