Greetings all. The Cruze Eco has a P0420 code (and it's been on for a week or so). I watched the O2 sensors during my commute this morning and both are bouncing between 0.1 and 0.9 (ish) at roughly the same frequency. I'm not in a state that does emissions, but I don't like seeing the money light on the dash either. Previous experience says the downstream should be cycling slower than upstream. Is that true for this little squirrel cage?
What else would/should I consider as possible causes?
Thanks in advance.
What else would/should I consider as possible causes?
Thanks in advance.