MY MAZDA 6 MPS 2.3 TURBO RUNS FINE . WHEN ITS NOT MOVING YOU CAN PUT YOUR FOOT HARD DOWN WITHOUT A FLUTTER BUT WHEN YOU ACCELERATE HARD UNDER LOAD (MOVING) IT MISFIRES VERY BAD. COMPRESSION IS ABOUT 173 ON ALL FOUR, NMAZDA HAVENT A CLUE , DIAGNOSTICS JUST SAYS MULTIPLE RANDOM MISFIRE. CAN YOU HELP. PLUGS CHANGED