Does anyone know where I can obtain a catalytic converter for a heat exchanger approx.5" diam opening&5-10"Lng

It's to replace the catalytic converter inside of a Prochem Legend heat exchanger , which is a truck mount carpet cleaning unit. The heat exchanger to replace is 1,000 US dollars! Unfortunately there is nobody who will simply remove the catayltic converter and tack weld in a new one. Instead, I am discovering that folks have to look high and low for a PROCHEM SEVICE CENTER AND PURCHASE THE ENTIRE HEAT EXCHANGER! It's actually a very large heat exchanger in comparison to the failed catalytic converter inside. The rest of the converter consists of a large stainless steel tank and coiled stainless steel tubing inside. The endcap which is the exaust inlet from the on board Kohler 2 cylinder gasoline powered engine is also in fine condition. It's actually very expensive to replace the entire heat exchanger if I can just aquier the needed catalytic component. I'd be willing to pay $200- $250, which is a far cry fro PLEASE SOMEONE HELP ME! I am getting to old to be running my portable.-PaulDoes anyone know where I can obtain a catalytic converter for a heat exchanger approx.5" diam opening%26amp;5-10"Lng
what i did in my pressure washing and cleaning business was to remove the cat converter, cut it open and take the guts out. may not be epa legal, but has a lot better exhaust flow. (had to reweld it shut when finished) (Mig expenses was probably $2.00 including the agron mix gas)