2003 Mazda 6 throttle position sensor?
 

I have a 2003 Mazda 6 with a V6. Recently it has been giving me some problems not wanting to take fuel at times and then other times it will give itself fuel. Sometimes the "AT" light will come on and it will not take any fuel at all. I will have to coast over to the side of the road and turn it off and back on to get it to take fuel again. Finally the computer light came on and I had it diagnosed. The mechanic told me it was the throttle position sensor and it was built on to the intake. He said I would have to replace the whole thing and not just the sensor. He also said I would have to take it to the dealer. Is there any truth in this? Has anyone had any experience with this? Any advice would be greatly appreciated.