Not to try to be a meanie here or anything, but I am sure glad you are not my mechanic.
So you are suggesting that he just throws parts at his problems?
Considering it is a newer truck, I definitely wouldn't be blindly condemning senors without testing them.
An ohmmeter can be had for $25 and you can have the mental capacity of a 5th grader and still figure out how to use one. I am willing to bet that someone on here can give him those resistance specs for his sensors. A good reason to visit the forums rather than the parts store right?
What I suggest, is up to him if he wants to do it or not. I'm also no mechanic, but I wrench on my own vehicles. I'm far from poor, so $25 here or there isn't a problem, as my wife spends $100's a week just in clothes. Besides, not to brag, but I bought a multi meter for $7 on sale last fall. Just be sure that the person using it at least reads the manual on basic functions. Sticking the leads into a wall outlet on the wrong setting can induce some foul language.
Anyway, there are links floating around (not necessarily model specific) for factory service manuals, they MIGHT have the specs of the sensors, I never really looked. For the price of the grief compared to the new sensors, I'd just replace them. He could test them today, and they could be shot in a month, or a year. I'd rather replace the sensors every 2-3 years instead of pulling them out, testing them, and reinstalling. If I'm going to pull it out, I'll replace it. IAC can be cleaned if one is careful. If the carbon buildup is heavy, again, easier to replace than to spend an hour cleaning it with the hope that you didn't move the plunger, in which case you'd have to buy a new one anyway.
Same with a battery I bought a few years ago for my Dodge. The terminals kept corroding after a year no matter what I did. I found myself cleaning them every few weeks until I had enough and bought a new battery. I've had good luck with it so far. I know what my time is worth to wrench on vehicles, and if I have to keep repeating a job it's better to replace the source of the problem, rather spending all that time in keeping it going just a bit longer. Granted, if ones budget is minimal I can see trying to salvage bits and pieces to get maximum useful life out of them.
Maybe it's just me, but a 2005 isn't a new truck anymore. If it was manufactured in 2004, then it could be six years old - already. Sensors have no real useful life. Most will last the near part of a decade, but with people buying from the lowest bidders on new vehicle parts, it's hard to say how long things will last. I have yet to see an owners manual where it states that any sensor(s) should be replaced at certain mileage points, or cleaned if feasible. I think it should be put into the regular maintenance schedule. At least, on older Dodges. However, it's too late for that.