Can the knock sensor 0304 "ghost code" be triggered without the presence of any other codes? I'm pulling an 0304 code after almost every trip. I also get an 0707 (Rear O2) code, but only about once a week or so. Most of the time, I get an 0304, by itself. I'm experiencing bad gas mileage and poor acceleration, so I know something other than the rear O2 must be wrong.

So the question is, is it necessarily the KS that's bad, or can something else trigger the 0304 code, without triggering its own code?

I tested the KS harness and got 500 ohms or so between one of the pins and chassis ground, although I do get an open circuit between the two pins (I'm not sure if that is normal).

 

My best bet is it is just the rear O2 sensor throwing the code. The knock sensor has been known many times to be just a dummy code that runs in coherence with the O2 sensors. I would just replace the rear O2 sensor and see if the code comes back.....