How do you solve P0141, p0161 error codes

My dad spins a 1998 F150 with a 4.6 engine and 245,000 miles. The catalytic converters have been removed for about a year, and the only two codes he gets with ForScan are related to the rear O2 sensors, which have been removed. The truck idles fine but struggles when accelerating. This issue just started recently. If he reinstalls the rear O2 sensors, will it fix the problem? Any help would be appreciated!

The error codes P0141 and P0161 generally point to a malfunction in the oxygen sensor heater circuit in your car.

Reinstalling the back O2 sensors could be helpful, but it probably won’t fix the acceleration problem completely. Engine performance may be impacted if catalytic converters are not present. Look for additional possible reasons such as vacuum leaks, ignition difficulties, or fuel supply issues. It is advised that a mechanic do a comprehensive diagnostic to identify the issue.