Code P0171 System Too Lean

[Juice]

lean issue seems to be popular i have 1.20 long term ufel trim readings which indicate 20% fuel addition which means not enough fuel or too much air ? how to find/fix

You need to find out why? It could be a number of items causing a lean condition. From a vacuum leak, fuel supply issue, or some mechanical issue.
Is it tuned?

 

[07 Boss]

I chased a lean code for a while and it ended up being an exhaust leak on the top of the header collector/mid pipe connection.

 

[Mustangk]

not tuned altho i do talk to lito and im working on getting him datalog because my tuner was locked by sct and they would not unmarry my old strategy so i can remarry it because im from california, i had gotten ford to reset my tune to stock tune and it changed my strategy and then sct support wouldnt unlock my tuner cuss i live in cali. but im wondering if 1.20 is stock value for when you reset battery ? right after resetting KAM does the car stay in open loop for quite a while ? or does it only stay in open loop until it reaches the required parameters of engine run time, o2 sensor temperature, and the other few parameters required. because my ltft are fluctuating with throttle % i thought the ltft was supposed to take a long time to change the values as they reflect long term changes of the short term, they seem to change as fast as the short term now

 

[Mustangk]

so I have a stft that's perfect but ltft is 1.20 at idle etc and gets a little worst 1.25 recently. Does it make sense to be like that. Alzo when I throttle lt goes down to 1.00