Check engine light on - Hummer Forums - Enthusiast Forum for Hummer Owners

Hummer H3T The popular H3 gets the added capabilties of a small pick-up, with the look and performance of the original H3.

Check engine light on

Reply

 
 
 
  #1  
Old 01-30-2018, 05:24 PM
Junior Member
Thread Starter
Join Date: Sep 2017
Posts: 19
Default Check engine light on

My 09 H3T check engine light came on, went to autozone for an OBD check, this code came out.
P0420 OBD-II Trouble Code: Catalyst System Efficiency Below Threshold (Bank 1)
Anybody had similar issues and what was the fix?

Thanks!
 
Reply With Quote
  #2  
Old 01-31-2018, 10:17 AM
TAINTER's Avatar
Senior Member
Join Date: Sep 2008
Location: SE Michigan
Posts: 4,454
Default

A number of things could be the p0420 issue. Check the rear O2 sensor itself and wiring/connectors or the Catalytic converter is plugged up. those are the major causes of it.
 
Reply With Quote
  #3  
Old 01-31-2018, 12:57 PM
Doc Olds's Avatar
Super Moderator
Join Date: Jul 2007
Location: Boat Town USA MI
Posts: 8,339
Default

Miles on the Odo is always useful info when asking a question.
 
Reply With Quote
  #4  
Old 02-05-2018, 10:38 AM
Junior Member
Thread Starter
Join Date: Sep 2017
Posts: 19
Default

Originally Posted by doc olds View Post
miles on the odo is always useful info when asking a question.
167,000
 
Reply With Quote
  #5  
Old 02-07-2018, 03:24 PM
Doc Olds's Avatar
Super Moderator
Join Date: Jul 2007
Location: Boat Town USA MI
Posts: 8,339
Default

My guess at that mileage, which is not a long shot, is it is time for a new Cat. Like Taint said, could also be the rear O2 sensor, or both Cat and O2?

Any reputable exhaust repair facility can put it on a scanner and run it to full operating temp and watch what happens to double check what it needs.

IMHO and experience, Cats go about 140K miles +/- before they toast.
 
Reply With Quote
  #6  
Old 06-16-2018, 01:21 AM
Junior Member
Join Date: Dec 2009
Posts: 8
Default

Originally Posted by Doc Olds View Post
IMHO and experience, Cats go about 140K miles +/- before they toast.
We'll see this fall maybe
 
Reply With Quote
 
 
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Dale Farr
Hummer H2
3
01-29-2018 06:23 AM
Justin Jones
Hummer H2
3
02-13-2017 01:44 PM
Poweraidion
Hummer H3
1
02-16-2014 11:26 AM
joenuzz
Hummer H1
3
08-21-2010 10:24 AM
deejaykaygee1
Hummer H3
13
01-20-2010 04:57 PM


Thread Tools
Search this Thread
Quick Reply: Check engine light on


Advertising
Featured Sponsors

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.