I have recently been having issues with my 2000 maxima w/ 54k. The ses light came on about two weeks ago so i checked the codes and came up cylinder 4 misfire and ignition signal. So i changed the plugs ran injector cleaner and did several other tune ups(none that would effect the problem, but it was needed). The problem disapeared for the most part up until a few days ago, then it seemed as if it came back worse. I ran the codes again and random cylinder misfire and ignition signal came up. The problem i'm experiencing is a "putting" at idle and through 1000-2000 rpm, and when i check the exhaust it puffs out of the tail pipes. I really would rather not bring it to the dealership. Any advice on things to diagnose would be greatly appreciated. A side note i have a ca emisions and i have installed a injen cold air intake.

 

Coils ... But let someone else chime in before you go change your coils

 

why not take it to a regular mechanic?

 

ignition coils... which one to change, I don't know; I replaced all 6 of mine. Didn't have time to keep replacing coils.

 

most likely cylinder 4 coil, you could always replace all six to be sure, but that is $$$.
i had the same problem - the first time i had the codes run it was random cylider misfire and ignition signal, I reset the ecu waited untill it realy ran like crap, ran codes again and ignition signal and a specified the cylyder that was misfiring came up. i replaced that coil and have been fine since.

wait a little while and run the codes again if it comes up cylinder 4 thats the bad coil,

 

coils, coils, those friggin crappy coils.

 

Wow, this is like a rare occassion where someone has this problem and actually ran a diagnosis for themselves

Congrats!

It is more than likely cylinder #4 coil because of the misfiring of cylinder #4.