2013 isx 15 2350 help please

[rraccerr]

Number 4 piston was shattered and broken where rings were. They said they had to check block and head for cracks. Remanded heads. Job was done by mechanic in Compton. Don’t know about counter bore. Same head just redone. Don’t know if egr exhaust is blocked. Got truck end of October when I put it in beginning of may. $14,500. My friend put it in this shops down I went to work for him. To pay cost and my home bills.
I am idling truck now and I see coolant holding to max level on truck after I drilled hole in the radiator cap. I’m in ohio and I need to get to california to do all test Rawze suggest. I did fuel injector test with insite because mechanic didn’t do it and never mentioned why I kept getting fuel injector 23456 not responding. I set the injectors myself. Mechanic didn’t know how to do it. It wasn’t my pick for mechanic. Now I’m playing the cards I was delt