2.0L check engine light/engine codes

I am new to the forum and hoping someone can help...
 
We recently bought a 1996 Cabrio w/2.0L engine (165K) and the check engine light is on.
 
I went to AutoZone to have the codes read and are as follows:
 
P0422: Catalyst efficiency low-bank 1 - The PCM has determined that the main catalyst efficiency for bank 1 is below threshold for the current engine operating conditions.
P0102: MAP/BARO or MAF sensor condition - The PCM has determined that the mass air flow input is lower than expected for the current engine operating conditions.
P0172: Fuel trim bank one condition - The PCM has determined that during testing, the fuel system for bank 1 was too rich.
 
Does anyone know what might be throwing these codes?  Are they common?
 
I reset the computer, but the light came back on.  Any help is greatly appreciated.  Thanks!

try the air flow meter first
it might be seting off the cat and fuel trim codes