Can anyone give me some help? My SES light keeps coming on.

The codes with an Actron reader are:
P1159 - Fuel trim additive bank 1 high
P1161 - Fuel trim additive bank 2 high

Codes with Peak R5/fcx 2 reader are:
OF 1C - Mixture control, idle, Cylinder #1 to 4
OF 1D - Mixture control, idle, chlinder #5 to 8

In simpler terms, what is the problem. It would seem that there is too much fuel going to the injectors. Is this an easy adjustment?