1990 Chevy Lumina after driving, engine runs rough and rich

I have a 1990 Lumina coupe with the 3.4 V6. While driving normally, I can come to a stop and experience very rough running rich mixture with black smoke coming from the exhaust. It will stall if you don't feather the pedal and continue driving. Then all of a sudden it returns to running normal if you shut it off for a minute. I checked the computer for codes and got several:
15 - ect sensor indicates low temp.
21 - tps circuit open, or voltage out of range.
23 - open or grounded m/c solenoid.
43 - tps out of adjustment or knock sensor signal error.
53 - system over volt (ecm over 17.7 v) alternator out of range.
To me it seems like the tps sensor is bad causing the extremely rich condition, could this cause the timing to advance because of excess fuel and then spike the knock sensor? When the engine is in this condition, I can hear a knock or noise from the back bank of cylinders.