Have ya ever cleaned the Throttle Body? Might not help but for the price of the repair i would give it a shot? I would also clean the MAF Sensor while i was doing the Throttle Body. BTW finding a cheap part for a newer Tundra will probably not happen too often but good luck! Have you tried a op tier gasoline? This might also be a waste of $$$ but for the price of that Sensor and Labor i would experiment a little!
guess Labor is main thing driving price up on replacement? Part is only 150.00 if you could DIY?
pdf below shows why the Labor would be so much and it starts on page 65 i believe and if it were me i would change both if i were to DIY! just to make sure i did not remove manifold twice!
http://www.tundrasolutions.com/forums/1179824-post1/ good tutorial!