They are cheap enough to replace so probably worth doing, but if its misfiring on boost its more than likely down to your spark plug gaps, sounds like the turbo is blowing the spark out. Take the plugs out and tap them against somthing hard, you want to decrease the gap on the plugs ever so slightly. You can do it by eye or you can use a feeler guage to get the correct gap, doesnt need to be much, just make sure you dont dent it to much that the electrode touches each other. Done this loads of times to fix misfires, works a treat :~0