I have had the P420 code pop up three times since I owned the car. Once about 5 months ago, for reasons unknown, the other two about 3 months, and two months ago, both after hitting a hard pot hole or bump I didnt notice.. Arlington has ****ty roads. The last time, about 2 weeks ago, was while the car was idling warm foor about 5 minutes it tripped.... not sure if it truly is the cat, or something else... wouldnt it come on more often if it was the cat? should I check my o2 sensors or no? just really hoping its not the cat.
The P0440 came up twice... both under a semi hard braking manuever, I know its commonly a gas cap, but what other things can it likely be on this car?
Any feed back is welcomed.
Added: Also wondering if its a o2 sensor because the best I've every got out of a tank of gas is 340miles with a light foot. And thats bone dry 17.2 gallon fill up. Ive heard bad o2's cause bad MPGs.
