Hey Y'all, 99 CRV throwing a cat code p420? I believe... I had it scanned at auto zone before leaving Arizona and driving to Colorado. About 3 hours from our destination in CO the engine light started flashing, we stopped, checked all the essentials, but the car seemed to be running decently still... Now whenever the car is sitting at idle it feels a little rough and the light starts flashing. I've never owned a car with spark plugs, but I'm starting to get to know my way around this thing, I've done the normal service, filters, oil, etc. Other than the rough idle it runs great! could it be valves? bad O2 sensors? bad cat? It smells like its running quite rich and previous to switching to a 5w40 oil it was burning about a quart of oil per 1k. Like I said, it still runs well and the light stops flashing once the vehicle is moving, but I'd really like to keep this thing on the road and running well. Thanks for any input!