Not jail, expulsion. The House ethics committee has no authority to jail anyone, including Rangel. They can issue fines, and make recommendations to the larger House body about censuring or expelling members.
The DOJ could still investigate and prosecute Rangel for tax evasion - but of course, we both know that this DOJ won't investigate Rangel. Even still, this "deal" will do nothing to insulate Rangel from criminal prosecution.
They couldn’t toss him, either, not if they need his vote. NYS’s gov Paterson has been denying NY-29 a prompt special election for months. If Goodtime Charlie resigned, Paterson coulden’t very well call an election for Rangel’s district while stiffing NY-29.