Need emissions help!!!

I usually post in the 4.6 threads, but this situation is in regards to my other Ford engine which is a '94 2.3L

I'll try to keep it short, but I want to give you all the info.

2 months ago: Replaced DHCP sensor, EGR valve, EGR solenoid & ran code reader KOEO, KOER and CM codes all came up 111 or 10. (Thanks for everyones help )

Yesterday: Wife driving home and engine overheated. I added coolant which solved the overheat problem. Engine started running rough so I pulled the codes and this is what came up

CM = 211 profile ignition pickup circuit fail
KOEO = 111
KOER = 172 HEGO senor fault/lean
332 insufficient EGR flow detected

I reset the computer without fixing anything, drove it around and pulled the codes again and this is what I got:

CM = 10 (all clear)
KOEO = 111
KOER = 332 insufficient EGR flow detected
411 cannot control RPM during KOER low RPM check.

My questions are:
1. Could the engine overheat have caused the codes and could it have cause a malfunction/failure of any of the parts I replaced?

2. Could a clogged cat cause the EGR problems that the code reader is pulling?

By the way I can't find any coolant leak and I'm not burning it. Flushed the system 2 years ago. So where is it going?