My 98 pathfinder check engine light came on and the engine was running rough. I went to Auto

Zone to get the OBDII error codes: P0300 Multi Cylinder misfire, P0301 Cylinder one, P0325

Knock sensor. They reccomened a tune up, which it needed: Plugs OEM, Plug wires, Distribitor

cap and rotor, Fuel filter, Air filter, Oil Change and to put some Lucas injector cleaner in

the fuel tank. These would be the first steps to resolve the the P0300 & P0301 codes. I

installed these parts and the check engine light went off for a while, but came back on. They

said the P0325 Knock Sensor code is usually triggered by other problems with the engine, such

as the P0300 or P0301-6. The next step was to check the injectors, you can
have the injectors power cleaned by a shop through the fuel rail for about 60.00 to 150.00.

You can check the injector function by disconnecting the wire clip on the top injector while

the engine is idling, the engine should stumble or run worse than when it is connected. When

I disconnected cylinder 1 on my engine the engine ran the same as if it where connected, so I

replaced the injector on cylinder 1 (P0301)and the problem was solved.

 

Good work; thanks for the detailed info.

 

p0300 p0301 p0302 p0303 p0304 p0305 p0306, p0325
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