At start up my truck will start to misfire and will do so until press the gas pedal to the bottom and hold it there until it shifts from low to second. The code is multi cylinder misfire all on the right side. Mainly 2& 6 but 6 the most. Have changed #6 coil, fuel pump, cats. And done a top end flush. Also took fuel rail off to check for water or trash. After I hold it there until it shifts I can go back to normal driving and it will not misfire again until I shut it off! But it doesn't happen every time.