Defining repairs needed to correct codes

Question

I HAVE had my mercury marquis to like four different shops. The codes are P0171,174,113, and 122. My last stop was at a ford dealer of which they had ran a cpmplete check with their puter and found the added later codes. They recoomend replacing the intake gasket, throttle body gasket, throttle position sensor, injector o rings, air intake temp sensor pcv valve. I am curious what others may thing or reccomend.

Answer 1

"replacing the intake gasket, throttle body gasket, throttle position sensor, injector o rings, air intake temp sensor pcv valve." 

sounds about right.