Now that part, I'm not sure is replaceable. The seam on that side of the radiator is where mine took a dump, and the whole thing had to be replaced. You may be experiencing the same thing, a seam break. Seeing that yours is a 2007 also, I'm guessing the radiator is probably done. Plastic fatigues over time, and it's now 13 years old.

 

Just for future reference that might help others with DOR/PZEV radiators, I saw you post in this other thread where I posted my solution so hopefully you are all set but all I did was solder a wire jumper across all 4 contacts, 2 on each side, routing the wire around the back of the sensor so that the car will think it's still installed properly. See here for more: https://mitsubishiforum.com/forum/mi...able-us-48069/