To bake the DPF or just get a new one?

Why not?

 

DPF Filter Cleaning Services | DPF Service and New Supply

 

How does baking remove the ash?

 

It doesn't. It has to be blown out. Usually its done by a machine using compressed air.

Understanding the Differences Between Ash and Soot | CTS

 

Why the need to bake? regen temps are higher than 400 degrees.

 

I've driven a couple of trucks where the DPF got baked. It turned out fine after that. 380k is way past time. Rule of thumb is every 250k, then you replace it 1 million miles. If the soot levels are too high, get ready to call a wrecker or creep it to the shop. The truck let's you know when it's time, more frequent regens, then regens not lasting more than 15 or 20 min, it's about that time.

 

Pic below from my Volvo manual, 2015 D13

NOT 400,000 miles. 400,000km (250,000 miles). I still go by 200,000. No problems.

 

Remember what's in front of the aftertreatment system - an engine. I've seen folks clean or replace the DPF due to too frequent regens multiple times before they realized the DPF was fine and it was the engine that was sick.