The purge function (related to p0441) is designed to occasionally burn off the gas that’s accumulated in the evap canister over time. This should only occur when the engine is needing extra fuel anyway, like during accelerations. It purging occurs at other times it can result in an overly rich mixture, and that could damage the cat over time. Your symptoms most likely seem like they are caused by a faulty, clogged cat. As pointed out above, if stuff has broken off inside the cat (a common enough thing), it can clog intermittently, then free up for no apparent reason. That’s what I’d focus on. If you can get it to happen at a shop, an intake manifold vacuum test would confirm or disprove that idea. Removing (not just disconnecting) the pre-cat o2 sensor (temporarily, as a test) is a common way to diagnose clogged cat problems also. That creates a hole in the exhaust system for exhaust to escape ahead of the cat, and if the symptom goes away it pretty much proves there’s something clogging the exhaust system somewhere from the cat to the tailpipe. Note that this will make a lot of noise. There are other possibilities but to me this sounds like a cat problem. Asking a shop to make sure the MAP holds vacuum probably makes, that’s a quick, easy to do test.
Took out the O2 sensor today and Drove for 60 miles in the country at various speeds 25 a 55 with a few stops and starts. No loss of power at all. Had three codes come up multiple times. 0125, 0130, 0133, but none about the purge flow or cat.
Since I most often drive short trips in town and seldom in the country I need to continue this test with short trips in town at slower speeds. I really would like to see that purge flow code pop up before I put the O2 sensor back in.
Will get back after a few more days on driving in town and hope I don’t get pulled over for driving without a muffler. Man it is loud!
With the O2 sensor removed you’ll likely be getting lean/rich/can’t-figure-it-out codes for that. Also the computer may not be able to detect the amount of purge flow with the O2 sensor removed. I’m not sure how it performs that function, but it might well use the O2 sensor signal. Hopefully the loss of power problem won’t return and all you’ll have to do is replace the cat to rid yourself of that. If the purge code comes back then you can work on that then. You don’t want to ignore it b/c the replacement cat could get damaged again. This would take quite some time so not an emergency, but must be addressed with due speed. Best of luck, good confirming of the diagnosis there OP.
Still running without the O2 sensor hooked up. Have not had to use the car much so will continue to run this test for now. No new codes other than the ones reported just above. Also no problem yet with loss of power. Will be interesting to see what happens when the O2 sensor goes back in.
Is the missing/removed o2 sensor the one before the cat, or after the cat?
Before. It’s on the end of the exhaust manifold
If the pre-cat o2 sensor is physically removed (not just disconnected) , and you get a major improvement in engine power, you have to consider the possibility that your cat is clogged.
O2 sensor back in and the car lost power at 25 mph after 3 blocks of driving and 2 right hand turns!! I guess that pretty says the cat. Is the culprit.
Thanks for all the help. I don’t think I would have found the bad cat. on my own.
Now to wait for warm weather (Duluth MN) to see if I want to replace the cat. and pipes (muffler?) myself or offer the car on Craig’s list for a few hundred and be rid of it.
The engine and trans have been fine but it has numerous electrical failings. It has been a weird electronic lemon. Auto door locks will lock and unlock themselves ALL BY THEMSELVES!! I kid you not. I had to disconnect that fuse many years ago. The doom light will turn itself on BY ITSELF! It drained the battery some years ago and so I took out the doom light bulb. Seatbelt warning light comes on at random! AC compressor is shot so I took at out and replaced fan belt with shorter one. Otherwise a great runner. Haha.
If you sell it, say the model is the Prizm-WorkARound … lol …
It’s a rebadged Toyota Corolla, so I’m guessing it could. 
Nah the Corolla is a Prizm!
I’m going to list it on Craig’s as: “calling all budding backyard mechanics your ship has arrived!”