Hello. I have a 2004 silverado with the 5.3l vortec. Check engine light is on with code P0327 (knock sensor 1 circuit low). Before I take off the intake and replace it, I was wondering if someone could tell me what steps to do to verify it's the actual sensor itself and not something else. I've read several forums where people replaced both sensors and wiring harness and that not fixing the issue. So far all I've done is unplugged the wiring harness and doing an ohm test from the side of the harness that runs to each knock sensor. I dont remember exactly which one was what, but 1 of them was at approximately 102 ohm and the other was approximately 101 ohms. I haven't pulled the ecm yet to check if theres a short in one of the wires that come from it to where it plugs into the knock sensor harness. I dont want to replace both sensors and the wiring harness and it not solve the issue. Also, from what I read I heard it is imperative to use only ACdelco knock sensors as other aftermarket ones wont read or work correctly. Any advice on what I can and should do to make sure it's the sensor itself would be greatly appreciated. Also, this is the first topic I've ever posted on a forum so I appreciate your time for reading this and possibly being some help to me.