What are some of the 2012 GMC Terrain catalytic converter problems?

Catalytic converters are an absurdly expensive part to replace on most vehicles, and the 2012 GMC Terrain is no exception. Therefore, You'll want to stay on top of components whose failures can run significant risk to Your catalytic converter. Namely, the leading cause of catalytic converter failure is the failure of an oxygen sensor, which leads to overly hot exhaust. This causes melting of the rare earth metals in the cat, and will lead to a clogged cat that won't allow exhaust to flow freely. Typically, if Your oxygen sensors are failing, they'll throw diagnostic trouble codes, readable with an OBD-II scan tool. If You see them, it's time to swap the oxygen sensor out; it may cost You $100 and You might not see noticeable engine performance increases, but it will save You a very likely $1,500 catalytic converter bill in the near future.