magarbhai

hi guys i am new here.yesterday i install the after market exhaust on my bike whick is xj6n 2013.this morning when i start the engine the temperature keep going up while i am riding it goes up and down somwtime goes to 122 and again 120 again goes up and the header gets so hot n coolant light comes up?any help would be great.i think its to do with header cause when i take out to stud and flange bolt from stock exhaust 2 of the them where broken half.when i install new one two of them i couldnt tight but no air coming out from it.how do i post pic i hav picture thanks.