too lean issue? p117B p0171 engine codes
 

about 4 weeks ago i had an issue with my car throwing a p2109 code for throttle sensor issue along with lean codes, what really happened was a small piece of black plastic got stuck in the throttle body after removing it that solved the throttle issue, but i still had lean error codes i took it to the dealership to check out the tps sensor and other codes they said everything was fine it was probably just the plastic piece i found... 2 days after, the lean codes popped up again so i just reset the ecu thinking they were just flukes, they have been constantly popping up for weeks and the dealership says they cant find anything wrong. I just got an oft tablet so i ran some data logging. my afr seems to fluctuate between 14-20 with normal driving around (1500-2500 rpms) the LtFT averages around 12-28 i dont think thats normal... and also the StFt fluctuates between -3-32, maf voltage goes between 1.4 - 2.4, im new to the tuning side so i dont know what much or what the average should be on a 91, ive tried applying the stage 1 91 oct tune as i am stock still but still similar numbers

does anyone know what could be wrong im trying to pinpoint it so i could tell the dealer or fix it myself?

data log
 

heres the log where the check engine light popped up during it

https://drive.google.com/open?id=0B1...3J3SFdMbk5KWHM