2005 Nissan Altima Q&A

2005 Nissan Altima Question: what would cause no fire to cylinder 4 to my nissan altima 2.5L engine?

I have replace both crank and cam position sensors,placed injectors, replaced spark plugs, and swap coils and I still have no fire to cylinder #4. -
Answer 1
poss computer issues do you have any other code than po304. you may need to seek diag on this -
Answer 2
Have you checked for ignition fire with a spark tester hooked to the coil to see that there is no spark? How much comperssion on #4? Injector pulse ok when checked with noid light? Coil feed circuit&connector ok? -