07 F250 5.4 engine no power
 

Brought the truck to the Stealership and just as I predicted they found nothing wrong....$150.00 out the window.

So I step on the gas and the more the pedal goes down the more it bogs down and wants to stall.
So far I have: Changed the fuel filter
Cleaned the MAS
Changed the air filter
checked for vacuum leaks
Ran a few tanks of fuel injector cleaner ...
Some codes showed up at autozone when the check engine light came on
0171, 0191...lean codes

So what's next to check? o2 sensor? Bad Cat? Fuel rail sensor? fuel pump?
I dont wanna start throwing money at parts... thanks in advance

Sometimes we forget the basics.
When were the spark plugs last changed?
Does it happen only when hot,cold?
Do you have any means to check fuel pressure?

From the codes you posted, the 171 is a lean condition and the 191 involves a temp sensor circuit.
A defective coolant temp sensor could be providing incorrect info to the computer, but without being able to see the readings which require a scan tool we're shooting in the dark and can wind up replacing parts that may not be defective.

thanks Hanky....trying your suggestions