96 Neon trouble codes and power problem.

My Brother in law just got a 1996 dodge neon 2.0L. He says it drives fine but when you floor it it doesn't really do anything (doesn't goes any faster) and is getting codes P0117, P0118, P0125 and P0171.

The only thing I can come up with is maybe the t-stat is stuck open or a bad Engine Coolant Temperature Sensor, but I havem't looked at it yet, I figured I would get some opinions, see if anyone had similar problem, from the forum before I go testing and tearing...

Joe