First I had a bad coil pack on the middle front cylinder. I replaced it and everything runs mostly fine except I do get some hesitation. I changed out my spark plugs for new platinum ones probably 12,000 miles ago.

I am now getting a P0304 code from my scanner so I looked at the front spark plugs.

Here is what the front left and right plugs look like
http://imageshack.us/photo/my-images/109/17804393.jpg/

Here is what my middle front plug looks like
http://imageshack.us/photo/my-images/52/74937416.jpg/

Is this what could be causing my error code or does it look normal? I checked my Haynes manual but it doesn't look as bad as the pictures. If it does not look right, then what do I need to do?

 

The middle plug looks like it is not firing. Maybe the coil pack you put on is not doing its thing. I hope it's not an E-bay special. Try cleaning the plug and swap it with another cylinder. Also swap the coil pack with another cylinder, but not the one you swapped the spark plug with.

 

1st plug look good. Second plug looks like either it's running wayyyyy rich or not at all.

 

On 8/18/2011 the op posted problems with his E-BAY coil packs:

http://forums.maxima.org/5th-generat...ed-advice.html

Various members of the org suggested he not get E-bay coil packs again. I was trying to ask (and rather poorly) if he was still using an E-bay coil pack on cylinder 4. If he is, that most likely is his problem.

 

I did not get the eBay coil packs. I got a replacement coil pack from an online parts place. The car runs much better with more power but still has slight hesitation, and rather than a P0300 code, I now have a P0304 where the previously broken coil pack was.

 

That middle one doesn't look too good.

Swap that middle spark plug with one of the outers and see if the misfire occurs in the other cylinder.

If the middle cylinder is still misfiring, swap that coil with one of the outers and again see if the misfire occurs in the other cylinder.

You should be able to narrow the problem down by doing that.

 

Do the swapping and see what happens. The P0304 only occurs from an electrical problem. If was strictly a plug problem, you would not get a code.