Service emission system

[TSV]

Need help i can't get my service emissions system lite off. It's says speed will decline to 65 miles per hour. It's 21at4 with 110k i just bought it now warranty I've topped off def. Code p21dd and p221e. Don't know where to start

 

AT4 Forum Fav 👍

American Flag Metal Trailer Hitch Cover - Grab one through Amazon!

[gemarsh]

You will need to replace the def tank. The heater is not a serviceable part. gm has/had a bad design on the def heater.

 

[gemarsh]

I found the tsb...

 

[pinebaron]

Sounds like an expensive repair.