nissan maxima knock sensor problem

For over a year, the check engine light on this 96 maxima would turn on, then after whatever the requisite start/run cycles (40-50, 100, whatever), it would go out, then come back on a few weeks later to repeat. the code suggested an O2 sensor and knock sensor. I didnt notice big problems with driveability or mileage, and since I dont drive too aggressively I didnt pay attention to any decreased power (from the bad knock sensor). Before replacing sensors, the car ran and sounded fine. Since replacing both sensors however, the car now has a slight but noticable pinging while ascending a nearby hill at

35-50 mph. It is an automatic, and even if I jab the accelerator to kick-down the automatic tranny to a lower gear and hence prevent any possibility of lugging, the noise persists. I thought I had that sensor installed correctly, but incorrect installation is the only thing i can think of that would cause this.

any ideas???

The knock sensor code is usually a red herring on these cars. It can come on with other codes and it does not set the engine light by itself. Its possible that you replaced a perfectly good one with a bad one, but more likely, as I replied in the Nissan group, that you damaged the wiring harness to the sensor when replacing it. The parts guys at Courtesy Nissan sell the wiring harness stub with the sensor as a kit because this is so often the case.

The knock sensor in this car is screwed into the top of the block with a single bolt in the center of the valley under the intake manifold. You can easily see it if you shine a light in there. If you have small enough hands or access to a 10 year old kid, you can reach in and touch it. Assuming you can touch it, it is possible to check that the wire is securely connected to it. Be careful though. The wiring on '96 Maximas is generally pretty crunchy by now.