How to fix rear catalyst on 2002 ford escape
You don't fix catalytic convertors, you replace them. You must be replacing it for a reason that it clogged. Fix the issue why it clogged first, usually a misfire.
Also make sure that all oxygen sensors are working properly, this can cause the vehicle to over fuel and burn out the cats. If the check engine code is throwing a P0420 it needs a cat. If there are other check engine codes address those first, its a long shot but on occasion it can resolve any codes for catalytic convertors. You should also call your local ford dealership to see if there's a reflash procedure out for that year, this widens the specs for o2 sensor readings to eliminate faulty codes caused by the recent increase in ethenol use in gas