error code P0170 fuel trim bank 1

so i have a 2001 volkswagen jetta wolfsburg. and at the beginning of the month my engine light came on. after getting it scanned it read P0170 fuel trim bank 1. after googling the causes of this code we replaced a rotted vacuum hose and cleaned the MAF sensor. then went and got the code cleared. now 3 weeks later it came back on reading the same error code. P0170 fuel trim bank 1. do you by chance know anything about this code??