Hi guys,
driving from Pittsburgh to New Jersey, I ran into the following: first, sudden loss of power, especially up hills, etc---pretty independent of which gear your in.  Later, power returns, but engine is very noisy---like a car without a muffler (although perhaps not quite that noisy).  Other than that, the engine seems to run fine now, and the noise, it seems, can only be heard from the outside---that is, with the windows rolled up, driving on the highway, you don't notice it.  Roll down the windows, or get out the car, and its VERY loud.

My thought was: some ceramic in my catalytic converter broke up, at first clogging the exhaust, but then breaking free and letting more exaust through---thus returning the loss of power, but muffling the engine noise less.  Does this sound right to people?  If not, what should I be looking for?  And if so, I can just drive it like this until I have to pass an emmissions test, right?  And how can I try to find a cheap cat?

Thanks very much for any help.  Oh---and the van's an '84 manual.

Another thing I noticed---there is still "exhaust" coming out of the tailpipe, but you wouldn't know it if you didn't stick your hand right behind the tailpipe---it's not black at all.

Thanks again,
Wes