1998 Chevy Silverado ENGINE DIAGNOSTIC CODES

1998 CHEVROLET SILVERADO
177,000 MILES • V8 • 2WD • AUTOMATIC
Avatar
TOMHAYES
  • MEMBER
  • 1 POST
I HAVE 2 CODES FOR MY TRUCK. THEY ARE:
P0420 AND P0430

Catalyst System Efficiency Below Threshold (Bank 1)
Catalyst System Efficiency Below Threshold (Bank2)

Can you tell me what needs to be done to correct these codes? I had a new Catalytic Converter installed 1 year ago. Thanks for your help.
Mar 8, 2008 at 7:54 PM
Advertisement
Avatar
BLACKOP555
  • CERTIFIED EXPERT
  • 10,386 POSTS
those codes are for bad cat's.

firrst thign to check is to see if the sensors are good, if they are bad replace them. also you may have a exhaust leak causing those codes to appear.
Mar 9, 2008 at 10:10 AM