So was driving my girlfriend home from work and my 1997 Maxima starting shaking and the check engine light came on. Went to O'REILLY'S and got a diagnostic test done and these 3 codes came up... P1320 P0325 P0303. Help please?

 

P1320 is a ignition signal and p0325 is a knock sen code and p303 is one of your cylinders are misfiring. The 1320 code is saying your coils are dying. Replace the coils all six. If your harness are not shorted it's good to get all the coils replaced now.

 

And don't worry about the knock sensor code yet. It usually comes on when other codes are triggered, and often goes away after the other problem is fixed.

 

agree knock sensor code could be related to the noises the engine is making misfiring. You have a p1320 with a p303 code so i would start with cyl 3 coil replacement. and if you plan on keeping the car long-term buy 2 and keep a spare with you.

 

It's better to replace all of the coils. The original ones could be tired and worn out. The change of one coil will out perform the other coils mpg wise. The ohms in the new coil will be better than the other tired coils causing a sluggish performance and bad mpg. This is coming from experience. The other tired or worn out coils ohms would be low or in average range. The best way is to use the nissan consult 2 power balance test of the coils that will explain everything.

 

I agree the best thing to do would be replace all of them for $240. but that's a lot to spend around Christmas. fortunately he has a code so one should be all he needs to keep it running for now that's all I was thinking

 

If he goes with one only in a matter of time the ecu will detect unbalance fuel trim and then throw the ses light on. This is why us techs at nissan when it comes to coils and plugs you want to do them all,if they have not been replaced .

 

New coil packs, new plugs, new lease on life!!!! Invest in Dielectric grease when you go back together...Apply into coil pack spark plug boot...Contains spark and prevents any voltage leaks.

 

I would look for uneven plug burning and a wet plug also. Swap a known working coil with the cylinder that is reporting a misfire.

The last time I had a shaking engine at idle it turned out to be from leaking injector o-rings that resulted in uncontrollable flooding on two cylinders.