Good Luck with this problem- It seems to be an all too comon error among us Dodge owners. I've replaced EGR, Cam position sensor, crank pos sensor, coils, IAT sensor, MAP Sensor. I am beginning to think the computer is fried but before I do that I will check for broken exhaust valve springs.
Get a can of mass air flow sensor cleaner and clean the maf sensor
p0172
P0172 System too Rich (Bank 1)
Code P0172 means: System Too Rich
This code is defined as: Output Speed Sensor Circuit
The problem is " P0172 System Too Rich - Bank No. 1 " That's going to be your oxygen sensor before the cat... it has gone bad. Replace it. http://www.fordf150.net/howto/eecvcodes.php
Trouble code P0172 means: System too rich (Bank 1)
Trouble code P0172 means: System too rich (Bank 1)
Trouble code P0172 means:System too rich (Bank 1)
Trouble code P0172 means:System too rich (Bank 1)
Trouble code P0172 means:System too rich (Bank 1)
Trouble code P0172 means:System too rich (Bank 1)