help P0420 code

i need help with my 1998 honda accord lx 2.3l !!!

the check engine light keeps going on and i keep reseting it

the first time is p0420 and my mech told me to jsut reset it, it is not a big problem

and i never knew what that meant

at times i got lazy and never reseted the code but my check engine light jsut went off on its own and during thanksgiving i drove over a HUGE BLACK HEFTY garbage bags and started to melt under my car.

3 days later my check engine light turned on so i went to AUTO ZONE and they pulled off the code P0420 and told me to change my oxygen sensor.

they told me it is the sensor before the CAT...

but the code states "P0420 Catalyst Efficiency Below Threshold (Bank 1) "

and i have read the forums and some changed their CATS and are fine...some changed their CAT is the light is still on...Some changed their Sensors and are fine while the others changed their sensors and the ecu code still shows...

ps. i forgot to mention i got the car at 91000 miles and i remember seeing a recipet wen the car was at 79000 he took it to a honda dealer and got his CAT replaced...don't that mean the cat is some what new and the sensors are replaced also???

honda- 1998 accord lx vtec 2.3l 97980 miles currently...

Maybe this will help:
http://www.obd-codes.com/trouble_codes/generic/p0420-catalyst-efficiency-below-threshold-bank-1.php

if the primary and secondary o2 sensors are ok, and there are no exhaust leaks, then, your cat is gone.

no current check engine lights for either o2 sensors right NOW?

thanks for the link and i have read it, but from what autozone and advance auto told me was to change the o2 sensor before the cat not after.

also had the cat changed a lil over half a year ago.

how do i check for a leak on my exhaust because it is winter and like i do see water driping off my exhaust when my car is warmed up...

also had the cat changed a lil over half a year ago.

oem or aftermarket?

how do i check for a leak on my exhaust because it is winter and like i do see water driping off my exhaust when my car is warmed up...

that, and you can feel the leak with your hands.

i got the car used and i remember seeing him wif a honda dealer reciept saying his cat was replaced. not sure if it is oem or aftermarket

and you said with my hands, so where should i place my hands and feel the leak?

wehre the cat is? where the exhaust? in bwt etc...

thanks a lot

the cat is under the car. feel for exhaust leaks at all connections.