I would greatly appreciate this forums help on this subject. I have a 1997 SE, automatic, 55k miles. I recently purchased the car, and afterwards, got an emissions test. A code came up saying "knock sensor 1 circuit malfunction" and the attendant told me to not worry about it (cause the engine light is not on).

What confuses me is that the car does not knock, or ping, or hesitate during hard acceleration. I use 91 octane (although I think the previous owner never did) The engine light has never come on, but every time I check the computer with my OBDII, the knock sensor code is there. I erase the code, and it comes back after a couple of days.

Any ideas what is going on? Is the sensor truly bad? I am also thinking that the spark plugs and fuel filter have never been changed, which could cause some predetination. I really appreciate anyones ideas, thanks a ton!!!

 

IF it continuously gives the code then yeah, something is wrong. There is another thread on the board about removing the sensor. I replaced mine a while ago, the part was $124. I was on vacation and bought it couldn't buy it from my usual shop. It is an important sensor.

 

Replace it, if it keeps coming back $125 or so from Courtesy Nissan.

It looks like a pain to replace though, as it's between the cylinder banks, below the intake manifold...

 

Join the club. Its the only code I have ever thrown.