u/HarbingerKing

Hey guys. 2009 Nissan Altima 2.5 (4th gen) with 120k miles. Recently had a code P0420 (catalytic converter malfunction) and got the catalytic converter and downstream O2 sensor replaced along with the valve cover gasket which apparently was leaking. All this cost me about 1/3 the car's market value. Now less than a week later my "service engine soon" light is back on and I'm getting a code P0128 - thermostat function/coolant temperature regulator circuit. Engine is running smoothly and there is plenty of coolant in the reservoir. Any way this is related to the work done recently, or just coincidence? Wondering if I should take it back to the shop that did the recent work (Midas) or try to replace the thermostat myself. Thanks in advance.