I haven't been able to get my '06 RL registration renewed because I keep getting emissions codes. 185k miles. I had a P0430 code along with these codes in the subject, but I replaced all O2 sensors, and that went away. I was still getting P0443 and P0497 AND I was getting the "check gas cap"...

I just bought the car, so do not know if there are mpg issues or anything like that. It has 203K on it, and it doesn't look like the previous owner was too much into preventive maintenance like replacing parts without codes. Here's what I have so far: The Codes: P0420: Rear bank catalyst...