Hello everyone, first of all my car has about 92k miles. While driving, the CEL light popped up and the VSC light also lit. I have an OBDII scanner and I check the code, the code is P0420 which is catalyst efficiency below threshold. I researched and some said that it could be the weather, gas, etc. So I removed the code and the CEL came back within 150 miles. Now I am stuck in a dilema. Can someone please direct me to what steps I should take now, what should I look for and what should I replace. I have also noticed that my gas mileage has decreased tremendously. Please someone help. Thanks and have a great night..
-Pablo