PLEASE HELP! P0171 ERROR

[Juggernaunt911]

Hey Everyone, just wanted to start off by saying that I love the site and found it very helpfull and full of very informative info.

I was driving along on the highway and suddenly the "service engine soon" warning lamp came up. Shortly after I had the diagnostic check done and the following error code came up "P0171 System to Lean Bank 1 (Left) " I did notice a little hesitation in power towards the hight RPM range as well.

It was pretty late in the day, so I thought to just fill up and try some fuel injectior/fuel line cleaner (not sure if that will help or not)

I am basically looking for suggestions (trying to avoid Dealer headache), I did some looking around through some related threads and they indicated that it can be possible vacume leaks,02 sensor and or MAF.

I am not too mechanically inclined but would like to take a stab at fixing this myself. Is there anyway I can clean the MAF or test this? To be honest I dont even know where it is located..lol

All suggestions and tip would help greatly!

Thanks for your help,
Tim

01 X5 4.4