My 2000 honda prelude blew out a oil cooler seal the mech. says change time belt to cuz its wet now doi really

Yes you do have to, when oil and grease get on a belt it weakens it, I know first hand. If it affected your timing belt I would definitely change it due to most Honda's being dual overhead cam DOHC, if that belt breaks you will more than likely end up bending a valve and / or punching a piston. That will cost a lot more money than the replacement of that belt. Get it done

facial cream