2006 M45 rough idle and drive

[trayday]

my 2006 M45 sport started ticking like a lifter but went away, a month later it came back running rough while driving/idle. On the way to the dealership my check engine light came on, after diagnosis they said cylinder 8 misfire with a bad injector and would cost $600, i had another place perform the work for $250. I picked the car up, stills idles and drives rough but not as bad, check engine light still on, the car idle fluctuates from 800-900 rpms. any ideas?

[EniGmA1987]

Might want to try performing the idle air volume learning procedure, its a long shot but worth a try since it is free to do. The procedure is somewhere around the forum here.

[mexillis]

Id go back to the place who fixed it and tell them its not fixed and leave it there until it runs properly. Don't drive off with it runnung like crap or if u don't notice it until a few miles down the road its better to turn around and bring it back then continue driving.

[trayday]

since Infiniti said it was an injector i thought it was legit, i took to the performance shop and told them to replace injector number 8 with a core charge and thats what they did. Today i also swapped coil packs and same code came up with my buddys scanner, it ended up being the spark plug. maybe when the injector quit working the plug kept sparking and burnt up?
Have you ever heard of the ticking sound for a misfire?