So yesterday I drove my 99 cherokee sport about a half hour from my house on the highway. It did great and all Temps were good but when I parked and shut it off it dumped coolant all over the ground. Boiled out through the overflow hole on my coolant reservoir. I let it cool down for a couple hours and then topped off the fluids and got to the nearest advance auto. Replaced the thermostat and filled it up with fresh coolant. She drover great the whole way home until about 5 minutes from my house. At a stop sign it started idling rough and the jeep kind of started shaking from idling so hard. Now it starts up and runs but it sounds and feels rough and the exhaust smells strong. My heat didn't work before the new thermostat and I didn't check after. Didn't see any coolant in the oil or any oil in the coolant but wanted to get some more thoughts on what might be wrong. Thanks in advance

 

Rough idle, high temps, exhaust stinks? Could be a partially clogged catalytic convertor, but it could be lots of things. In what way does the exhaust stink? Does it smell like fuel? Rotten eggs? What color is the exhaust? Is the CEL on or flashing at all?

 

Hi the CEL was on before the problem started due to a bad o2 sensor. It started running rough after I drove it so I pulled it into my garage and changed the o2 sensor and I am still stumped on what the issue might be. The exhaust smells strong, I guess like full but not 100% sure. Just stronger than it did before. Haven't seen the exhaust color yet but can check. I did notice that the cat stayed warm long after I had shut off the jeep and the rest of the exhaust pipe was cold but the cat was pretty warm. I hope it's not the head gasket but I do have a new one to put in if it did go.