its running like its on 4 cyl. cleared the codes and it came right back. this thing is putting like a yugo! 98 max gle. have looked up the codes but they dont really point to a prime suspect.. any and all info would be most helpful to come up with a way to attack this and these issues. much thanks in advance

Codes - random cylinder misfire, cylinder 6 misfire and knock Senor.

Clearing the codes isn't going to magically fix it. You are going to have to change something.

I've found that a defective ignition coil is usually the culprit of a misfire..in this case Cyl. 6

Swap in an OEM ignition coil....OEM NISSAN.

And the knock Senor is an easy swap..takes 20 minutes

Really? to think that i would think that it would magically fix it is insane. i have allready swapped the coil packs and it still comes up same issue. i am by trade an aircraft mech. what i need is a guru to help me get a start or ref point. much thanks though.

Well you did say, " cleared the codes and it came right back". That comes across like you cleared the codes and were surprised that they came back.

As for swapping the coil, if the problem is still present you may want to look into other things

Crank or Cam sensor going bad, faulty wiring, there are a ton of things that could cause a cylinder misfire.

If you swapped your coils and the misfire stayed on cylinder 6 then the coil is good. How long ago did you change your plugs last? What is their condition and brand? If you have changed them recently with NGK ones you are good there. But that means you either have wire issue or ECU is bad. I am no guru, but I have had to deal with misfires on few of the Maximas I have owned.