I have three permanent codes. p0420(bank 1 catalyst efficiency below threshold), p0430(bank 2 catalyst efficiency below threshold), and p2097(bank 1 post cat too rich). I've since had the car tuned but these codes remain because of the permanent status. I'm trying to get rid of them so I bought an o2 spacer and put it on bank 1 to try to get rid of p0420 and p2097 first). After a few cold starts to get the cat tests to run p0420 disappeared and p2097 changed from saying (permanent) after it to saying (SES, pending, current, permanent, history). I immediately went into the tune to p0420 and changed it from (SES on, MIL 2nd error) to (SES on, report no error). I flashed that tune and after it flashed I went back in the scanner to check codes and p0420 was back saying permanent again. I'm so confused as to what happened. It was gone so I turned it off in the tune and flashed and it immediately reappeared. I hadn't even started the car yet. And p2097 changed to just saying (permanent) after it again. The code was finally gone! What happened to bring it right back after a flash!? Could the code be stored in the tune? I just don't understand how it was gone and a tune change brought it right back!