I set the frequency for an ILS approach, and instead of lining up on 161, the plane holds steady at 166. How do I correct this problem so the plane will line up with the center line. Thanks.

What plane is it? Default?. I know that wind drift is taken into account so your HDG will be a few degrees off most times.

For all planes. Default, add-ones, payware. Thanks.

Which airport?Some airports have offset ILS where the localiser doesn't align with the runway.

Also check gyro drift...