When missfire happens I have left engine running then have removed l/t wireplug connection to each coil in turn. Right hand bank of cylinders all have power to them, left hand bank all power has been shutoff. If ignition is shut off then engine re-started the engine runs fine again. During normal driving the problem does not occur, it only seems to happen after hard acceleration and the engine using high revs say over 4000rpm, during acceleration there is no problem it is only when you ease off the gas the engine then misfires and always on complete bank on left side as viewed from inside car, right side if you are stood at front of vehicle looking at engine. Missfire will not clkear until engine is shut off and re-started.