My question is if I can swap 6 with 4 to see if it is indeed the coil or plug. I mean that would throw a different code if that's what it was right?Please know that I probably sound ignorant but I'm just a single mom trying to fix my car
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I'm not sure if a different code will appear...if it specifically states which cylinder is the culprit. I don't think it does that, but I'm unsure.

When my coils acted up I bought two new ones, one for the front style and one for the rear style and had to swap them out one by one to see which one was bad. That was a long time ago so maybe i didn't even have to do that. I had just bought the car so it was all new to me.

 

If the coil is bad and you swap it to a new cylinder, it should follow to that cylinder and throw a P0306 instead.

 

Yes, to decide whether it's your #4 spark plug, or your #4 coil, swap the coil and see if the problem moves.
However, you should be aware that P030x can be caused by a number of other problems. They are less likely, but possible; see the EC section of the FSM (to download the FSM, see the link in my signature below).

 

no codes however my car is dying after idling a while it drives great starts right up. But the code reader on live data says catalyst and oxygen sensor does that mean they are going bad or what?

 

Just wanted to tell you that when i switched # 6 and #4 no codes where thrown?It just ran a little different
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It may take a few drive cycles to throw a code. If it's running differently now, that tells us there's something going on with the coil.

It could be that the coil is weak and was slowly letting the #4 plug get fouled to the point where it started misfiring enough to throw a code. Put a stronger coil on it and maybe it's enough to fire through the fouling. The clean #6 plug may work with the weak coil for a while.

I'd pull the plugs and inspect them all side by side. You may find #4 looks dirtier.

 

After changing the ignition coil the error p0304 cleared Now it will start right up. But, dies if i am idling to long. Then it won't start acts like no fuel. Even if there is a quarter of a tank. So i put more gas in and it started. So i got the code reader because the CEL was just barely on fluttery if you will. So it still throws NOCODES. Okay, so now I have been driving light comes on then goes off. So what do you think now. Changing the oil that is all I can come up with. Haha I should have done that already. But I would like someone else's opinion. Not on the oil change but anybody experienced this fluttering of the CEL.

 

A flashing CEL light indicates a severe (and possibly multiple) misfire. For some strange reason, this condition usually does not throw a code .... perhaps because the problem is too random. At any rate, to prevent damage to your catalytic converter, so you should rectify the problem as soon as possible.

I would suggest the following:

• Check for codes. In spite of what I said above, I would check for codes and/or "incomplete" monitors. If you don't have an OBDII scanner, get one; you can't maintain this car without one, and these scanners are now quite inexpensive, like here:
  Amazon
  Amazon
  .
• Coils. The most likely cause of your problem are bad coil(s). This is especially true if your car is a 2000 model on which the original coils were never replaced. The original coils on 2000 Maximas had a design problem and most of us had to replace them. The new/updated coils (made by Hitachi) can be recognized by a "gray dot" (see the 2nd picture here: http://www.rockauto.com/en/moreinfo....359222&jsn=378 ). If you order them from Rockautop.com, it will cost you 3 * ($35 + $37) for all six coils. See here: http://www.rockauto.com/en/catalog/n...tion+coil,7060 .
• Spark Plugs. I would also check the spark plugs. Start with one on each bank. If they look bad, check all of them, and replace them as necessary

To summarize, you want to verify that your coils are good and your spark plugs are clean. BTW, I don't believe in testing a coil by measuring its resistance; the coil is an electronic device, with a power transistor inside, and it takes a lot more than a simple resistance check to verify that it's functioning properly.

 

I fix this issue just last week, here goes:

- start car and let run for up to 2 minutes
- unplug the electrical plug from the top of the coil and listen if the engine ide drop. Then plug back electrical and do the same for the next plug.

This is the best start to isolate each coil.

If you unplug a coil electrical And the engine doesn't idle poorly, then bingo.

Next, move suspected bad coil to another position. You will get a P0300 at first, and repeat the above exercise. A new code will appear if that bad coil is moved