It's not common for the Throttle position sensor to fail, but it does happen.

Your getting a new MAP sensor because the new TB comes with one.

 

BTW since you are getting a new TB with a new MAP make sure they do the TSB....I would hope the new MAP sensor(and tie down) would come on the new TB. If it doesn't ask for it. WIth the amount you're paying for the new TB it should be done.