Why are the Flowmaster super 40 on my Ford Fusion Silent?

I have a V6 ford fusion with dual Flowmaster super 40s 2.5" center in center out with resonated tips. I also removed the exhaust resonator but the sound goes away after around 2700 rpms. when i floor it all you hear is the engine. i also have 3 cats but i dont know much. i just want it loud at high rpms too so please help thanks|||Y'all is probly gona need tah brake em in. How much did the system cost cause my mom wants ta put som on her 08 fusion? Try goin to YouTube and search ford fusion with flowmasters. Prety cool video