Paccar mx13 - lack of power

Started happening about a week ago. Wrench check engine light came on and the truck drives like I have 30k in the box, even when empty. Occasionally the light goes off and engine has full power, but it comes back on after just a few secs and power drops again. No boost gauge, but oil, temps, etc all normal.

Truck does still do regens, so don't think it's a dpf issue. Can't do parked due to the wrench light, but it still does rolling regens.

Thought it might have been the fuel filters since that was the problem last time I had power issues. But nope, changing them did nothing.

I don't have a boost gauge, so thought maybe the turbo just wasn't running. I pulled the hose off between the turbo and charge air cooler and started the engine, turbo was blowing air out while idling, and a lot more when I upped the idle to 1500 rpm. Of course, I don't know if it was a normal amount, but it was certainly felt strong to my hand.

Any of you mechanics know of anything else I can check?

 

Was hoping to avoid that, lol.

But anyway, delivered my load I Denver last night and came to a kenworth shop. Just needs a nox sensor replaced and a doser nozzle in the dpf.

 

Yea, truck was back to normal after the nox sensor was replaced.

The doser nozzle had been a somewhat old issue, it just made the dpf take a long time to get hot enough for a parked regen.