Engine misses on 2002 Chevrolet Avalanche 2500

My engine misses when it idle and when I drive it.So I tried changing the spark plus ,spark plug wires and the number 7 ignition coil still give me reading on number 7 cylinder when i check it with the diagnostic tool so I swap the coil 1 around with 7 and still get a reading it number 7

Asked by for the 2002 Chevrolet Avalanche 2500
1 answer
check injector, or maybe poss wiring problem to injector or coil or even bad computer, or poss bad cyl, also do compression check