I just bought a 2000 gt Ford mustang bout the beginning of July and many a month ago I my car started missfireing in cypenders 1 and 5 and it would lose power if I stepped on gas pedal. I changed coilpacks, coilpacks wireing, sparkplugs, sparkplugs wireing, air intake manifold, air filter, gas filter. And even after all that it still losses comperesion at about 70 mph and continues to idel rough. I lovey mustang, is there anyone out there that has a answer or sulotion for my car