Clunking and Smoke

[1993Saturn]

I've got one that I have never heard of before, hence my question to the great minds of our community. Engine runs rough and code says rich. The auto trans seems to shift fine. After warming up, there is an occasional thunk, somewhere, like a bad backlash but louder. Soon, there would be multiple thunks, there is a drop of power and pedal to the metal doesn't help. I can go about 25 mph. Then there's smoke. It comes from under the 2nd cat.
These are my KOEO codes:
341 - Octane Adjust svc. pin open
566 - 3-4 shift solenoid circuit failure KOEO
629 - Torque Converter Clutch (TCC) solenoid circuit failure
173 - Heated oxygen sensor indicates rich condition, right side
177 - Heated oxygen sensor indicates rich condition, left side
543 - Fuel Pump circuit open; Battery to PCM

Now, Tag, you're it!