SES Light Off and On -P0430

I have Uprev, catted Cajun B-pipes, JBA LTs and cat back with UQ resonator. I've had them on now for about a year and a half. I had one issue last summer with the SES light coming on and pointed to P0430 (bank 2 below threshold I think). I reset it and it stayed off until this summer. It has came on and stayed on for several days before going back off again maybe 3 or 4 times this summer. Any ideas why it would trip and then 'correct' itself before tripping again a few weeks later??? Thanks in advance for the inputs!