99 Blazer Knock sensor

OK, I'm blind but I have some rattle/pinging at full throttle and sounds like timing but I can't find that knock sensor anywhere and see no wire leading to the rear of either head, above the starter, or by the temp sensor (2 wire connector on drivers side head) vs the 1 wire for knock sensor. Anyone know the exact location on a 99 LT Blazer for blind old me? The TPS was junk too so changed that but no effect on full throttle pinging. Thanks.

Should be loated passenger side, rear engine area, below end of valve cover, mounted in cylinder head.

there should be two knock sensors. check here for componet locations: http://www.autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/18/ba/42/0900823d8018ba42.jsp

On my '97 theres only one and it's up on the engine block behind the distributor....kinda the same location as the road draft tube on a 265 if you're as old as Eric...lol. A mirror and strong light might help.