Knock Sensor 2002 Nissan Frontier

I'm willing to bet you have weak upper O2 sensors & there's nothing wrong with your knock sensor. But if you want, the knock sensor is under the lower intake manifold in the back that is located under the upper intake manifold also called the upper plenum. The lower intake manifold is wedged between the 2 heads and is an enormous pain in the azz to get to. You can check the O2 sensors with a scanning tool that will show you the upper sensors in bank 1 & 2 bouncing electrical current from about .5v to 5v several times per second. Anything less show weak sluggish sensors. The resulting lean mixture causes a knock. Change the sensors and the knock goes away and so does the engine light after you reset it. It took me 6 months to find this problem after replacing everything else including the 6mth old O2 sensors fresh from China. Now I have Bosch. PS The lower sensors went 2 weeks later & I was told any more problems it's the fuel regulator. 2001 Frontier 3.3l v6. No problems since, it purrs like a kitten. I'd suggest the Bosch, it's a special design for that 3.3l engine.

Bypassing (hotwiring) the knock sensor will remove a signal the computer needs to operate. Unexpected results for sure , possible damage to the computer may result. Replacing the knock sensor is the best way.

The pcm uses the knock sensor to monitor for engine knocking, and adjusts ignition timing based on this. If there is no knock sensor present, you will wind up with a hard fault that will keep the check engine lamp on continuously. Also, the truck will go into a more conservative driving mode to prevent knocking.
The knock sensor for a frontier is not terribly expensive, but it is a pain to access on nissan v6s, under the intake manifold

under intake

The knock sensor picks up vibrations from detonation and sends a signal to the engine computer, which then adjusts the igntion timing [ retards advance ] to correct it. You can read the operation of the sensor with a full function scanner, if it's working then you have to look for a physical problem with the motor causing the konck.

no but the knock sensor does send a signal the ecm and it will ****** or advance the distributor timing

Go to a different dealer. The dealer should know what is wrong with the vehicle by the codes. Don't let them keep guessing what is wrong and having you replace random parts.

the knock sensor on a 3.5L should be just under the exhaust ports on the right side of the engine if you're facing the side with the pulleys and crank(front) for the life of me, I cant remember if the engine is mounted longitudinally or tranversely in the frontiers.....lol. There should be a wire going to a small black thing thats just kind of there,... its really easy to miss. if you can, check the nissan forums or somewhere online the e-manual that should have the exact placement of it in diagrams.

IF YOU REPLACE SENSORS YOU HAVE TO ERASE PCM CODE TO TURN OFF CHECK ENGINE LIGHT.IF YOU DONT IT WILL KEEP LIGHTING UP.

knock sensor is located on the block usually under the intake. nissan has problems with these sensors. i have chaunged plenty of these on nissans in the past year. this has no affect on your gas mileage. this sensor picks up misfires on the engine. sometimes you might have rough idle and can't feel it in the drivers seat but the knock sensor can. i would suggest maybe a tune up spark plugs, air filter, fuel filter first before going to take apart a bunch of things to change a sensor. the sensor is designed to pick up any differences in motor quality and will throw the engine light on. sometimes the problem is the knock sensor, or there is an underlying cause that the knock sensor is reading.