97 F350 4X4 manual 60 thousand miles.
The truck seems to run fine when first started. It has less power after it warms up than it used to, idles slower, and idles rough. It was leaking fuel in the valley. I changed the blue hoses and I think it stopped leaking.
I read several other threads and people suggested unplugging the ipr. The truck will not start with ipr unplugged. So, is the ipr bad, the sensor bad, or ??

 

The IPR is not a sensor, and the engine will not run without it.

How's the oil level, and how old is it?

 

Oil is full, changed a month or so ago, less than a thousand miles.

 

Most likely they meant for you to unplug the ICP on the driver's side oil rail. This will cause the IPR to regulate the HPOP to 700 psi at idle. There are quite a few reasons for the truck to run rough at idle.

If you have a way to check for codes that may help diagnose the cause as well as what was already suggested.