I replaced both sensors about 4 months ago. have had several knock sensor codes this past week, all showing bank 2 low input. I also replaced the connector, from Napa, for the rear sensor when I replaced both sensors. I am wondering if I have a bad sensor or connection, or if there is a problem in the wiring. Is there a way to test the sensor and the harness? I still plan on replacing the sensors again, and the harness(GM this time)