I have a 1994 Jeep Grand Cherokee Laredo inline 6 4x4 (auto). I recently took it to O'Reilly's auto parts and had them run a diagnostic test on it and they told me I had a bad knock sensor, I purchased a new one but I can't find anything on the web or anywhere else that can tell me where it's located on the engine. It's been jerking while driving after about a 30min drive or so, the idle will drop, rev up and drop again. If anyone has had a similar problem I'd appreciate any and all help, thanks.