P0325 Nissan - Replaced with brand new knock sensor, Cleared code, drove 30 miles, CEL back on.

Question

So now with a brand new sensor and the CEL coming back on after only driving 30 miles, any suggestions what the problem could be? And how I can go about fixing it myself?
(Also quite annoyed mechanic never informed me "the purpose of the 60 day extension inspection sticker was because after replacing the knock sensor I have to drive the vehicle about 50-60 miles and make sure the "CEL" remains off! ...60 days ran out on July 28th.... and after speaking to the shop, the city hall, the pd, and the dmv, all they could tell me was "Oh well, (You're) s.o.l....." Just...great...).

Answer 1

P0325 Knock sensor circuit malfucntion Bank 1 or single sensor

Before going into the knock sensor, coolant level or fluid in the radiator should be checked, Oil level should also be checked before going into the knock sensor. Because the year make and model there is the igntion timing that should be checked, You may not have a faulty knock sensor, some other situation can be the cause for the knock sensor to set a code. And with this year make and model mostly all  Nissan  have a knock sensor in the pending code that does not turn the CK ENG LT on.