loud knock while accelerating that increases with speed

[stumpee1]

while driving my 06 grand prix started knocking loudly (no ping, loud knock). the knock increases in speed as I accelerate (like a card in bicycle tire) its kind of like I can feel it in the accelerator pedal as well. it only happens while driving is fine giving gas while parked. Does anyone have any ideas? my catalytic converter is in rough shape as well if that helps? connected problem?
ty for any possible assistance

 

[Scottydoggs]

it do this in park and idle or if you rev the engine? if so your engine died.

 

[stumpee1]

it only happens while driving. I just checked and its fine giving gas while parked. (I was just editing my thread for that reason when saw this lol)

 

[Scottydoggs]

axle then most likely, should be vibrating pretty good too.

 

[stumpee1]

it is vibrating, can feel it in gas pedal. tyvm for help