Engine light on. Diagnosed as No. 6 Cylinder

[kebrom]

The engine light came on and so took the 2003 H2 to Autozone were they put their machine on it and confirmed (as my mechanic said same thing with his machine) that it is the No. 6 cylinder. The guy at auto zone said it was the plug or wire or coil. So I replaced them all but the engine light stayed on. Now, I just did the work yesterday so does it take some time or cycling of the engine to turn itself off? Is there anything else that the code could pick up besides those three in the No. 6 cylinder?