Piping from Cat back Vibration sound

[SilviaS14KA24DE]

So far, I've removed the heat shelds above the cat, stock muffler, and the shields below the downpipe - and still I have that annoying vibration sound.

Tomorrow I will remove all the heat shields from the cat, back to the muffler. Since already removing the cat and the muffler shields, the next thing is the sheilds wrapped around the piping. I'll post what happens after, for those who have this annoying problem.