I am working on a 2002 Chevy Silverado with the 5.3l. I keep getting error codes P0327 and P0332, which are low voltage to knock sensors on bank 1 and 2. It seems as if the knock sensors aren't working at all as i never get any knock when i am scanning as i drive, and I use to get little flairs of knock here and there.

I was modifying my exhaust just before this problem started and i was wondering if the voltage that goes to the knock sensors are on the same circuit as the o2 sensors behind the cats? I unpluged one of the post cat sensors as when i modified the exhaust i stripped the o2's threads and didn't want to buy a new sensor.

So does the voltage for the post cat o2's use the same as the knock sensors? Also where are the knock sensors located on these engines, I couldn't find it when I was looking today.

thanks for any and all help