ISX 871 525hp No throttle response

[Biglentil]

So other day hauling grain on a realively warm day temps around 30f my 2008 kenworth T800 550000 miles Stop Light came on and it went into total limp mode. Got er pulled over just barely shut er down. Shut power off and 5 mins later started her back up. Turned around and she drove home just fine. Was getting a crank case pressure warning on dash. So replaced the crankcase ventilation filter to the open element kind. We had a terrible blizzard so pulled her into the shop for further investigation. Cleaned the IMAP sensor and exhaust pressure sensor. Checked codes only getting one a 4214. Tough to find good info on that one. Also outside air temp not registering on dash tried to find the sensor its not under the mirror i have steel simple ones, and not in the front bumper area. Pulled it out for a test and now stuck in full limp mode no stop light, zero throttle response just idle. Did a forced regen took an hour no improvement. Inspected turbo on intake side seems fine. Pulled egr venturi tube full of coolant explains why truck has been going through some coolant. Egr cooler must be leaking. Could not bust 10mm bolts to egr valve wiggled back n forth for 15mins and stripped the head arghhh. Truck does alot of idling and very short hauls around the grain farm. Ive read the warnings about egr delete but this truck operates in some really cold like up to -40f and hardly leaves the farm. When cleaning grain in winter it has to idle all day. It might get 10000 miles a year and farmers are exempt from safety inspections up here in Saskatchewan. Im leaning towards this delete kit
A local shop called smokem diesel will program Ecu for 2500. Also delete the dpf . What should I do? Thanks in advance!