Just got my car back from Mitsu and had all the little issues taken care of (Replaced my cat, new AWC pump, services, ect.) i notice now i get a clunk sound when i start up my car. Seems to be coming from under the car and it is pretty distinct. It is getting louder little by little, not drastically. No codes came up but i want to catch the problem (if there is one) before it gets worse. Anyone have any idea of what it can be?