ses light
ses light 
there was some way to reset the PCM its on here prolly about 50 times...also try disconnecting the batter and such..pressing the brake with the accessories on/off etc. otherwise get it scanned either you do it or have AutoZone do it for free and come back here with the code
TECH Senior Member
Joined: Dec 2001
Posts: 5,399
Likes: 3
From: Jacksonville, FL
P0420 is most likely a bad driver's side cat - leave it stored and see if your local dealership will replace it under the 8yr/80K federal emissions warranty. If you want to reset it first and see if it returns reset the PCM by:
Turn key on, don't start car
Pull PCM BATT and PCM IGN fuses in the engine compartment
Wait 5-10 min
Turn ignition off
Replace fuses
This method doesn't affect the radio theft deterrent feature.
Turn key on, don't start car
Pull PCM BATT and PCM IGN fuses in the engine compartment
Wait 5-10 min
Turn ignition off
Replace fuses
This method doesn't affect the radio theft deterrent feature.
