have code 325 and 301, 325 is knock sensor, 301 is misfire on #l plug, what can cause this problen,car runs but is mising on #l plug but has fire.
misfire on plug #1 on 1997 Nissan Altima
start with a tune up and replace the coil for number 1. the 325 is what is called a ghost code. the 325 in the early years always went along with another code. if you fix the 301, 325 will not return.
my car had the same codes but the miss fire was on cylinder 4 turned out to be a pluged intake manifold try unpluging the egr valve by pulling the vacume line off plug the vacume line with a screw and drive the car see if the miss fire goes away