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.
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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