Also for some DTC it would NOT be just on off cycles but a full warm up from cold to auto clear a DTC if no errors are found. Some DTC would also need multiple clear full cycles to self clear. It is possiblle even on self clear DTC could be stored in history.
Depending on your driving habits readiness test might take several days or weeks to complete.
This full warm up cycle from cold is required to run the emissions readiness test. The readiness tests are the self tests the vehicle is conductinfg but only happens under very specific driving conditions.
Each specific emmisions area has it own readiness test examples EGR, misfire detection, converter efficiency, evap etc.
If your state has non running emmision test they (the state) are checking for passing readiness test in specific areas. Most states are looking of 6 or 8 readiness tests to test and pass with no DTC. This type of readiness testing was change to stop the owner from clearing DTC's and going directly to emmisions check station before the DTC resets. Readiness tests show as pass.......failed.......not run
MANY other DTC sensor related like ECT, IAT self check on every key cycle and self check continously while running. These DTC are looking for a connection to the ECU plus many are looking for a value that makes sense for the current driving conditions.