It is correct that a maf could cause one bank to read lean, but, 9 out of 10 times will read lean for both banks. I would look at the upstream o2 sensor. These are usually the culprit. Read the v6 tech column. I had similar condition except code 171 lean for pass bank. O2 all the way in my case. An air leak, rotten hose, improperly sealed something or other, bad pcv.....there are multiple causes and to be honest if the maf fixes this I will be surprised. Worth a try for a quick cheap fix if it works.