Hi, my 97 maxima gave a CEL on and i checked the codes and got the knock sensor and rear 02 sensor. I drove it back to the dealership i got it from because it was still under warranty. On my receipt the said that they replaced the 02 sensor and they removed, cleaned and lubed the KS and put it back. I didnt know you could repair a KS, i thought you had to purchase a new one? Do you think they just reset the code?

 

They lubed the KS? That's a new one. Maybe they put a little electric contact jelly on the harness connections or on the bottom surface of the KS. Did they charge you anything for that?