I just changed my knock sensor. Despite the Youtube videos (which mainly seem to be about the CR-V), you cannot access the sensor from above. As per the service manual, you must remove the plastic air dam from the bottom of the car and reach up to the sensor. This is easier said than done. I found getting to the sensor with my big hands a RRPITA.
I suggest that anyone with a high-mileage engine who has to replace their starter (which requires removing the intake manifold) should consider replacing the knock sensor at the same time, even though it costs about $60. There is no better time than when the intake manifold is off to swap out the sensor, and it's the
only time you would be able to clean the contact on the connector.
Oh, and after replacing the sensor, I reset the error code three or four times, and it kept coming back on. I was resigned to having the engine light on forever and checking every week or so to make sure a new code hadn't popped up. But after a couple of hours of driving, the light went out. Go figure.
Service manual:
Helm Inc.
H&A