Here is what the tech gave to me: IDS test P2291 ICP to low engine cranking in continuous memory. Test drove and got engine to operating temp and monitored the IPR% and the ICP pressure during engine starting, found IPR % going too high.

The IPR % should be 20 - 30% during engine cranking. When at operation temp the IPR % was goiung to 80%. Possible causes are high pressure pump, ICP sensor {checked OK}, IPR valve or leak in the injection control pressure system. Most likely there is a leak in the ICP system.

Recommends: Removing both valve covers and high pressure pump cover and performing air pressure test on IPR valve and if IPR valve is ok, air pressure test ICP system to find leak. Must retest after any repair.

I am new to diesels, great with gas powered stuff. Is this something for the pros, or could I fix it?