1999 Chevy Suburban OBD Code/wet weather

1999 CHEVROLET SUBURBAN
175,000 MILES • V8 • 2WD • AUTOMATIC
Avatar
JIMST
  • MEMBER
  • 1 POST
driving in rain/wet weather..."check eng light" illuminates. Code P0430 on code reader...Code reader turns out light...After 10-20 miles CEL returns.As weather clears up (dryer) the problem disappears, and does not return until the next rain/wet weather cycle....... HELP
Nov 16, 2009 at 2:57 AM
Avatar
PEAR69
  • ✓Experienced Mechanic
  • 1,482 POSTS
A p0430 means that one or both of your oxygen sensors on Bank 2 is either, sensing that there is a problem with the catalyst system efficiency, -and/ or - the oxygen sensor is failing. It could also mean that there is an exhaust leak..
First, check for exhaust leaks.
Second, test the two oxygen sensors on bank 2. It is a good idea to just test all 4 oxygen sensors. If they pass ---check all the wiring and connectors associated with the oxygen sensors. Third, have an air flow test performed on both catalytic converters to determine which one (or both) may be not working..
If all of that fails we will move on to the fuel delivery side of things...
Nov 16, 2009 at 5:12 PM
🔧 Tools & Auto Repair Parts
Find automotive tools, diagnostic equipment, and replacement parts for your next repair.
Shop on Amazon →
Paid affiliate link. As an Amazon Associate, we earn from qualifying purchases.
Add a reply
Join 2CarPros for free, one of the most advanced car repair communities on the internet. From first-time drivers to seasoned mechanics, everyone is welcome to reply, share details, and get better answers. You can add a temporary image or video first; uploads are limited to 20 MB.

Ask a new question

Frequently Asked Problems for This Vehicle