I have a 1990 Jeep Cherokee 4.0 and I was trying to replace the heater core cause it was clogged and was leaking so it was beyond a flush and it was causing my jeep to over heat so I by passed it for about 4 months now and now I’m trying to replace it I have the dash all out of the way and it’s just the heater core and the firewall. My problem is that the heater core/ the box it’s in will not come out. Please help. Thanks in advance.

 

Heres a pretty good write up....https://www.cherokeeforum.com/f51/dash-removal-35444/

 

Double check that ALL of the bolts in the engine bay are removed, and maybe pry on it a little bit. There is some sealing foam that may be keeping it stuck.

Pushing on the evap core or heater core hard-lines should also help to detach it from the firewall

But double check all the nuts there are a few that are not as easy to spot in the engine bay