Engine Management Light Code

Hi

I wonder if you could assist me i have a 2003 53 Plate Freelander with 1.8 K series engine the engine management light came on
we have had it on 2 different readers

The AA Code P0172 Fuel Trim bank 1

Garage Code P0170 Fuel Trim bank 1

The garage as replaced the lamber sensor but it as now come on again please could anybody shed a little light on the issue
Thanks

Not my area of expertise but have a look here
Click

Bank 1 appears to be the Co sensor (Lambda sensor) before the CAT but it does not indicate a fault with the sensor itself according to the info