Catalytic converter question

I've got a 96 Explorer with 218,000 miles on it. Lately its been hesitating. Had it in the shop and they say it's the catalytic converter. They say that since it has O2 sensors before and after the converter that I have to get a factory replacement and wanted $1,000 to replace it. Rather than replace it I had them try to flush the system. They added some fuel injector cleaner, an oil treatment, and did some type of fuel induction service. They said to run a tank of gas and that this might buy me 3 months to a year. Well, the first 40 miles I drove it it ran great without any hesitating but the last 80 miles have been very rough. I don't feel confident driving my Explorer in this state as I use it to pull my boat on the weekends. I did find the converter for a better price ($700) and am thinking that I'm just going to have to bite the bullet and have it replaced. Should I run more fuel through the system or just replace it? It is the original converter. Is it common for a clogged converter to cause hesitating?

1. you should post this in the "explorer" forum. 2.2 sraight six (moderator)may not like this.
2. A clogged converter probably won't make a vehicle run at all. I don't know of any cleaner that can fix this temporarily. Get a converter for your specific vehicle on ebay or someplace cheap. And get another shop opinion cuz exhaust work doesn't take that long so it shouldn't cost you 1000 bucks (unless it was a really expensive cat).

Is it common for a clogged converter to cause hesitating?

yes, that's a very common effect of a clogged converter. it's either plugged up with various impurities or the material inside has "moved" back and there's not enought "space" for the exhaust gas to pass through. it just causes a lot of back-pressure and the engine can't rev much because it can't flow the exhaust out.

is cat under the car or right up by the manifold? a good test of whether it's plugged or not is to remove the cat and rev the engine. if it revs freely and easy without the cat then that's the problem. just be warned, running a car without the exhaust system is ungodly loud. and don't run it for too long because you don't want to damage anything with the hot exhaust. (this may not work with the positioning of the O2 sensors.)

it's not cheap to fix, catalytic converters are expensive. (they contain platinum) so expect to pay $700 upwards for a new one. it's worth getting a new on instead of one off a scrapped vehicle. they have a limited life-span, so getting a new one is the best option if you plan to run the car for another few hundred thousand miles. it's not hard to replace yourself. unbolt old cat and O2 sensors, bolt new one in.