Dakota Forumz banner

1 - 9 of 9 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter #1
2000 Dakota Quad 4.7L. Wonderful Cali smog req every 2 years on my Dakota. Went to smog test and tech said it failed due yo O2 sensor not ready. Told me Cats passed, but couldn't say which O2 sensor was "not ready". A weak battery could cause problems with the electrical in O2 sensors but not sure if that was it. Replaced battery.
Question is should I just replace the sensors that previously gave fail codes. Tried driving it like tech suggested to clear but next days test new smog test still showed "not ready". No P codes whatsoever.
Months back had "check engine" light related to possible bad cat, I reset and added Catclean and it hasn't come back on. Befuddled!
What should I try?
 

·
Registered
Joined
·
517 Posts
You don't need to got to the test facility to see if all monitors are showing ready -- you can have monitor status read at most auto parts stores when they check for codes. I'm attaching a document I found a while back (maybe here) that explains drive cycles for specific monitors. The last two are for the O2 sensors and O2 sensor heaters. If your O2 sensor monitor is not showing ready after running the drive cycle, you may need to replace a sensor. If you know someone who has a scanner that can read live data, you may be able to determine which (if any) sensor is not providing appropriate data.
(Sorry about the readability of the document, unable to upload MS Word document)
 

Attachments

·
Registered
Joined
·
115 Posts
So I'm not saying this is the cause of the failed emissions test, but I remember several Cali Dak owners saying they had to put a 3rd cat on to pass inspection.
 

·
Registered
Joined
·
115 Posts
Okay, so it's possible that the Cat clean damaged the o2 sensors. Modern sensors, even 20 years ago sensors, are very sensitive to chemical additives. Did the tech tell you why the o2 is failing? Because there's several different reasons why they could be. Since you have no codes, I'd be a little suspicious. Ask why o2 sensors are failing. Depending on the reason, I would probably try replacing the o2 sensors first. Then look at the electrical system if that doesn't work.
 

·
Registered
Joined
·
23 Posts
Buy yourself a cheap code reader that has the capability of reporting on the status. It will save you s lot of time and trouble.
 
1 - 9 of 9 Posts
Top