Ok here is the rundown... large cam in a 01 5.3, started pulling timing, picking up false knock (hopefully). Changed the knock parameters to some 02 z06s bc apparently they are less sensitive. Drove awesome! No knock retard, timings good, parked it, and today fired it up for another test run did great got it up to run temp drove 20-25 mins everything is good, cut the truck off sat for 10 mins fired it up and check engine light came on... po327 knock sensor 1 circuit low bank 1 or single sensor, and knock sensor 2 circuit low bank 2. Erased the codes let it sit for 45 mins, cranked it back up drove for an hour, cut it off for 10 and light comes on right after startup. knock sensors are new...?

 

Did you use oem knock sensors or aftermarket? I checked for possible other failures for this code and tons of sensors and harness connection issues at the sensor. Pinched harness.

 

I used aftermarket :/ ive checked the plugins and the whole harness is new, its not all the time either, that is the weird part. Im going to replace them with some oem ones and replace that harness also. We will see how that works.

 

There was a bulletin years ago on intermittent p0327 and you were supposed to get rid of the end seals/foam and use a small amount of silicone on the rubber caps that go over the knock sensors to keep moisture out of the wells that the sensors sit in. I would say maybe when you install the oem sensors add some dielectric grease to the plug and then seal the caps, and see what happens. My old truck had a similar problem and this stopped it for me.