It's the Exhaust Backpressure Valve. AKA: EBV or EBPV.

Yes there is a sensor that plugs into a tube, and this tube gets clogged with soot. The sensor sits on the front of the engine, just behind the idler pully. You'll see the sensor attached to a metal tube that runs all the way to the passenger's side exhaust manifold. Unbolt the sensor, and run a long wire brush through the tube to clean it out. Also, very gently clean the soot off the tip of the sensor. Put it back together and you're done. Hopefully that will fix your codes. If not, then the sensor is probably toast.

As far as having a miss at idle or hiccup at cruising speed, the EBPV will not cause this. If it's not functioning properly, it will cause a very sluggish truck, low boost, and high egt's. Sounds like you may have another issue with the hiccups. I'd suggest keeping a spare CPS handy, that might be what's about to go out on your truck.