i changed primary o2 sensor last month and then did a valve adjustment a couple weeks later cause i had a missfire all problems were great.. its been weeks i duno how long exactly maby a month or so but i was driving home from work and the check engin light came on so i hooked up the code reader and it gave me p1165 for the primary o2 sensor but thats some bull casue i allready put a new one in... if anyone had the same problem with this it would help to give some times....the car is a 1998 honda civic dx d16y8

 

If this is an aftermarket sensor, be suspicious of it. OEM is highly advised for Honda oxygen sensors.