Cracked Exhaust manifold ????

Could a Cracked manifold could cause a bad idling?

i have a few things to check before i jump to this conclusion, but i can hear my exhaust coming out of my manifold from Cyl 4 louder and louder every week

I don't think it would actually make it idle worse, it would surely make it noisier though.
It might the gasket at between manifold and block, or the gasket between manifold and collector.

Could a Cracked manifold could cause a bad idling?

i have a few things to check before i jump to this conclusion, but i can hear my exhaust coming out of my manifold from Cyl 4 louder and louder every week

I had the same issue. The right side maniford was cracked. This required the shop to replace it. Picked one up at the salvage yard for 9 bucks. The repair cost was 100 bucks. Beats the noise and aggrevasion.
Good luck.