Since it's just one side lean, I'd suspect the O2 sensor on the left bank. If it's been a long time (if ever) that you've replaced those, it might be the right time. You might also run a cylinder balance test (booklet that came with your scanner will tell you how) to see if you might have a bad injector.
Since it's just one side lean, I'd suspect the O2 sensor on the left bank. If it's been a long time (if ever) that you've replaced those, it might be the right time. You might also run a cylinder balance test (booklet that came with your scanner will tell you how) to see if you might have a bad injector.