I got an engine code for catalytic converter under thresh hold and its eating my gas every time i start my car takes about 15 miles off a gallon with out moving.. Where should i look first...
thanks for your help..

 

exhaust leak..o2 sensor..or cat

usually not an o2 sensor with that code but i have seen it happen

 

get a catless d/p. call it a day. fyi our cars have 100,000 mile warranty from the dealer on our cat...

 

any way to fix it with out changing cat?