Hopefully it's a quick, easy, & cheap repair. I'm by no means a mechanic, but another possibility might be an EGR valve. I've gone through 2 of them on my previous truck. It would run OK when it was going, but idling was a miserable experience, having one foot on the brake & one on the gas to keep it revved up enough so it wouldn't die. Not too bad of a repair, if I recall correctly, and I even had it done at a dealership, so there should be affordable places to have it done, if that's the problem.
That is so full of suck Dyson doesn't know how they did it - shankyknitter