update
i took off the cat and the flap is still there and its preaty tight so thats good, and the cat looks in good shape as well
i even performed a smoke test leak and its not leaking anywhere ..
i went to check on the pancake valve i ordered and it performs like mine, if you blow both ways flow will pass true , so no point on changing that, i returned it
but wile we pulled out the cat and the 02 sensor .... i noticed something strange ....
the 02 sensor bong was 100% white .. why is that ?!
and the vag com reading are weird .. too much fluctuation .. , i will upload a video later of this ... its weird
and the knock sensor cyl #4 is weird .. all of cyl 1 , 2 , 3 are about in the 0.600v h +-, the cyl 4 0.950v is weird and when i rev it get even worst