Does anyone have check engine codes, son has a P0128 on an 08 Mega Dually 6.7 6 speed auto. He will be seeing dealer if open tomorrow but was curious.

 

thermastat rationality

 

My truck throws that code when its cold anything below-10C (around 12F).
It takes longer for the thermostat to open than the computer thinks it should so it throws the code. (According to the local dealer)

I have had it 2 times now - I just clear it off and it and I'm good until its cold again!

 

Myfirsttruck,

Did they ever replace your thermostat? I'm getting mine replaced at noon today for that code.
I only have a 1,000 miles on her; just hoping this is a long term cure.

 

no they said there is nothing wrong with it