Missing Link

We went this afternoon to bring the RV home so we can set it up for the trip we begin on Tuesday.  As soon as I started the engine I knew something was seriously wrong.  The motor ran but it sounded like an army tank and there wasn't anything coming out of the exhaust tail pipe.
    Sometime between 6 weeks ago when we parked it and this afternoon someone took a saws-all underneath and removed the catlitic converter.  Likely to sell to get drug money.

I know what I'll be doing tomorrow.