Question98 Altima 2.4 just bought the car 127xxx mi.Put plugs,rotor
cap,and,wires on new.Check engine light came on once,before
I changed the previous items.Hasn't came on since.I pulled
the codes,had 4.P0325 knock sensor 2 times,P0301,cylinder 1
misfire,P1448-fuel delivery malfunction.Like I said,I don't
know how long these codes have been there,except,I saw the
light come on once,before I added the new items.My question,
how can one tell,or,detect a faulty knock sensor,and what is
the ramifications if it is bad,and,not replaced? Adding to
that,what advice would you offer on the other two codes-
P0301,and,P1448? I know that's about 3 questions,but,I would
appreciate any advice you would offer!!!!! Thanx
Von,I might add,the day I test drove the car,I hadn't
driven the car off the lot before I noticed it missing,
the guy came out and found water in the plug hole,he said
they had washed the motor,and got it wet.They replaced the
plugs with new ones,and it ran good.I think that is where
the P0301-misfire code came from. The next day I changed
the wires,rotor,and cap.
AnswerPhilip,
The codes sound consistant with an engine that had been washed. The misfire code should be cleared to see if it comes back. If it does change the plug to another cylinder and see if it follows the plug. If it does replace the plug. If not replace the wire. If that does not do the trick check the compression. If the compression is good check the injector. The knock sensor will be a code by itself and if it is thrown replace the knock sensor. The car will go into limp mode, a pre programmed computer program designed not to hurt the engine. It generates too much gas and retards the timing and that is where the bad mileage comes from. The code P0301 is for number one cylinder and the P1448 is for the vent system. Either the gas cap is loose or defective or you have a vacuum leak in the fuel system. The fuel system is closed and if there is a rotten hose or bad clamp or loose or defective gas cap it will throw this code. Disconnect the battery for five minutes and this will clear the codes and after you reconnect and drive the car for three times you should recheck the codes. Autozone or Checker will check the codes for free.
