I was getting a 420 code, I replaced both o2 sensors, still got code, put in spacer on rear sensor and code went away. a year later and now I am getting a 2270 code. Anyone else get this code? I took out rear o2 sensor and tested it and it seems fine. for Haha's I didnt put the spacer back in, and of course the 420 code popped up 200 miles later. I am thinking I need a new cat. Any other ideas or am I screwed?

 

The 2270 is a lean fuel trim (ie too much O2 in exhaust) on bank1, sensor 2 (post cat). The bank refers to which of the two exhaust pipes is at issue. common causes as you know are bad cat, wonky sensor, or an exhaust leak (typically at the flex pipe). You may be able to have a shop check the flex pipe for leaks/cracks etc and possibly weld in a replacement flex pipe before biting the bullet on installing a new cat system.

 

Yes, put the spacer back on the rear sensor and drive the car. Save your money for something that needs to be fixed.