You mention having replaced your Honda Accord's oxygen sensor and EGR valve. If we understand the matter correctly, your Honda Accord has trouble completing the emission monitors, yet does not have the check engine light ON. Having replaced the oxygen sensor and EGR valve might not have been the required fix. A confirmed defective oxygen sensor or EGR valve should trigger the Check Engine Light on.
When you mention the mechanic said he is still reading the same 4 emissions, we are going to assume the problem is that the emission monitors (4 monitors - O2, EVAP, EGR, CAT) are not setting (turning into READY status) the fix involves getting your Honda Accord to complete a drive-cycle. If your Honda is unable to complete a drive-cycle, then those faults must be diagnosed. The replacement of components related to the "monitors" which are still incomplete is not necessarily the repair(s) required.
Whether the smog station you are dealing with explained this to you, we are uncertain. But it should be know that a particular emission monitor being incomplete does not mean the component that monitor is testing is defective. An emission monitor may not "set" for many reasons. The drive cycle may not be met, the drive cycle may have not initiated, parameters required to set the emission monitors may have not been met.
Finding the root cause of why an emission monitor is not becoming complete (or being READY) can be many and will require hands-on diagnosis.
Read more on How to Complete a Honda Accord Drive Cycle here.
