Just got a new 09 last week. After 1 day the check engine light comes on. The dealer resets it thinking it might be because the truck had been sitting on the lot so long. It comes back on in about 35 miles. Take it back in today and they put a new one in. Same thing going down the higway about 70 mph and after about 35 miles it comes on again. Take it back to the dealer and they give me a loaner and are going to try again tomorrow. Anyone have any ideas as to why it keeps throwing the code for the o2 sensor?

 

This may not apply in your case and I'm not even sure if this is possible on these things but a few years ago I had a gasser doing that and found that the factory idiots had plugged in the sensors backwards so the pre catalyst O2 was plugged into the post catalyst connection and vise versa.....made for some really weird readings and a ton of codes.

 

Just talked to the dealer, and that is what it was. There is two sensors and they were plugged in backwards.

 

Ain't that something.


Glad you got it sorted out.

 

Good one! You nailed it... Almost unbelievable.