Ford mustang - year 2000 - 3.8 liter The car is running but low power. It feels like it's down a cylinder. It is not running smooth. The ''check engine soon'' light is flashing.I've been told it's the coil pack by a mechanic that won't work it until Monday....today is Sunday. Is the coil pack is out? How hard is it to replace? It looks easy to get to. Any Advice?

I WOULD NUMBER ALL WIRES.MOVE THEM OUT OF THE WAY MAKE JOB EASIER.TRY CHANGING FUEL FILTER.CLEAN FUEL INJECTORS.FILL UP GAS TANK.PUT A BOTTLE OF INJECTOR CLEANER IN FUEL TANK.IF YOUR PLUGS AND WIRES HAS 10000 MILES ON THEM CHANGE THEM.MAKE SURE YOU PUT BACK THE SAME PLUGS THAT COME WITH CAR.YOUR SPARK PLUG GAP IS 0.054.HAVE EXHAUST SYSTEM CHECK FOR RESTRICTED MUFFLER OR CATALYTIC CONVERTER.HAVE TIMING CHECK.BOTH CAN CAUSE LOW ENGINE POWER. I WOULD NUMBER ALL WIRES.MOVE THEM OUT OF THE WAY MAKE JOB EASIER.TRY CHANGING FUEL FILTER.CLEAN FUEL INJECTORS.FILL UP GAS TANK.PUT A BOTTLE OF INJECTOR CLEANER IN FUEL TANK.IF YOUR PLUGS AND WIRES HAS 10000 MILES ON THEM CHANGE THEM.MAKE SURE YOU PUT BACK THE SAME PLUGS THAT COME WITH CAR.YOUR SPARK PLUG GAP IS 0.054.HAVE EXHAUST SYSTEM CHECK FOR RESTRICTED MUFFLER OR CATALYTIC CONVERTER.HAVE TIMING CHECK.BOTH CAN CAUSE LOW ENGINE POWER.