So I just got the car ready for winter with new tires and it's running great. Then I get a CEL yesterday. p0430 bank 2. So far i've read that it's either the Cat itself or just an 02 sensor. This is a nightmare scenario because you can Spend over $1000 replacing the cat and 02 but a rich running or misfireing engine couldve caused it in the first place. but that's just it. The car runs great. if it was a cylinder misfire or rich gas why did it not give me those error codes? Recently I changed the fuel filter and threw some injection cleaner in the gas tank. Really hoping it's just the 02 sensor. Also, if it's running rich how can I check for that and fix it?