RV need help Chevrolet forum was a waste of time....

Thanks to all. It is so diffucult to get at the engine to just swap coil pack. So I changed out the spark plug and coil pack on cylinder 7. I will try to get it out on the road and see if that clears it up. Does anyone recommend a fuel injector cleaner I put in Gumout or something to that effect.
Thanks to all