DEF = poor quality DEF left me stranded

I heard of some one putting a quart bottle of ammonia in to bring the concentration level up. DEF turns into ammonia when heated.
Or just drain out the tank and refill with good quality DEF.
A regen is what is required to clear the de-rate. But the NOx sensors have to detect a proper NOx level (good DEF fluid) for it to complete properly.

 

An emissions delete may seem all rosy, but it may come and haunt you in the future. Not all dealers will work on the truck, and when it comes to selling the truck, not everyone will be willing to buy a truck that is violating EPA regulations, especially a dealer.

 

My local Freightliner has a similar sign. They will work on it, but absolutely no warranty on any work done .