Help me out with this two codes!!

[erick0071]

i have a 94 escort and i just put a new motor in it ...but when i had the old motor in...the check engine light would come on ( i never bother to check for codes) but know that i have a different motor on the car...the light still comes on and now i checked the codes and it came up with codes:

172-lack of HEGO switches,indicates lean

332-EGR valve opening not detected

Is this possible even after the swap of motor i did or did the computer stored the old codes and is giving me the codes from the old motor.(the KOEO code was 111 this means OK but the above codes are Continuous Memory codes) What do you suggest? And what does each code mean?
I am not mechanic skilled but i learn rather quick and i am willing to check the motor myself if there is someone willing to help me out with this. Please post your replies . I am gonna check everything you suggest.

[Car Pal]

172, vacuum leak or top sensor.
332 plugged throttle body port.

[Jet-Lee]

172 - Bad O2 Sensor, not sure which one though.
332 - Either vacuum to EGR valve is nonexistent, or your valve is stuck.

Here's what you do:
172 - Take to a dealer.
332 - Pull the little hose off the EGR valve, with the engine at idle. Apply 8 hg of vacuum to that little port. Your engine should idle REALLY rough or try to die. If not, get a new EGR valve or take it to a dealer.