1998 Accord EX, 4 Cyl ...P0420..What is needed

Presently have 81000 miles on the car. The check light came a week ago ..had it reset ..it came agin after running for 30 miles
As per the OBD meter (Actron CP9125) it has
P0420
MIL ON
MONITRS
0 INC
8 READY
MISFIRES
FUEL
COMP
CATLYST
EVAP
02 SNSR
02 HTR
EGR

What am i looking to replace with so many options:shakehead

See if this link can help you:

http://www.automotiveforums.com/vbulletin/showthread.php?t=901851