2001 Buick Century 3.1 Codes P403 & P405

DTC is P403 & P405. Engine lacks acceleration power but will motor along at low throttle position and even gain speed to about 68 MPH total. On full throttle it bogs down and, at times, will not pass 35 MPH. I have Autoenginuity and it shows the timing to be around 15-20 when running somewhat OK and then at 40-44 when it bogs down(I can supply the spreadsheet of activity if you desire).

The EGR valve on the valve cover seems to be unclogged - the metal weighted plug inside moves easily when shook. Does the EGR sensor need replaced?