exhaust rattle
 

hello again , @ 1800-2400 rpm I have a buzzy rattle, like any thoughts, heat shields? possible cat?

Could be the heat shields on the precats or on the catalytic converter itself.
Other possibility is resonator after the main cat.

Do a search on Heat shields or rattle.

mine does the exact same thing, it was the heat shield, i went over a speed bump the pushed the shields in