Smoke from DPF

What color is the smoke?

 

If it was a dark blue or purple that usually means the diesel that is ignited to clean your dpf isn’t burning completely and it’s smoking because it’s landing on the hot parts.
The usual reason for that is your doc is getting plugged.

If you wanted to spend a few hundred dollars you could have a mechanic do a regen with the software connected to the truck and they would be able tell you if you’re plugged.

Does it have a strong metallic smell sometimes? Has the dpf or doc ever been baked?

Depending on the last time it’s been baked, it’s probably worth wild to have the dpf and doc baked as a preventative maintenance instead of throwing away a few hundred bucks to see if you have a problem.

Google the dpf maintenance schedule for whatever engine you have. Dpf is like brakes or tires they have to be maintained.