Feedback Carburetor System

The feedback carburetor system will set trouble code 16 under the following circumstances:

Use of an improper tachometer can set code 16. If trouble code 16 is displayed in "D-Check" mode, conduct the check again using a different tachometer. If code 16 is now absent, the tachometer was the problem and the feedback system is okay.
If code 16 is still displayed when using a proper tachometer, check if code 32 (oxygen sensor) is also displayed. If not, the mixture is too lean or too rich and the problem is something other than the feedback system. If code 32 is present, troubleshoot the oxygen sensor system and repair as necessary.