I've just changed mine, the symptoms of a bad icp sensor are.
the truck will lurch forward, kind of like you gas it quick and let off, it doesn't do it all the time when the sensor is first going bad (such as mine). it would do it more often when it had been sitting for a while. but if it was plugged in it would only do it maybe once in a 10 mile drive.
its definately not a cheap sensor, and if you replace it make sure you replace the pig tail as well since it could be the sensor that is bad or a broken lead in the wire. my 04 was easy to change, its in the pass. valve cover. if you have an 03, its up under the turbo. good luck