When do you see emissions issues?

THIS INFO PERTAINS TO A PACCAR ENGINE, BUT EMISSION SYSTEMS ESSENTIALLY THE SAME, I ALSO USE A APU AND HAVE LESS THAN THAN 4
% IDLE TIME. MY TRK HAS 500k JUST PULLED DPF FILTER FRI AND TOOK IT DOWN TO KW TO HAVE IT BAKED 2ND TIME. PROBLEM WITH THE FILTERS IS IF YOU WAIT UNTIL THEY ARE COMPLETELY PLUGGED THEY CAN ONLY GET THEM THEM SO CLEAN, ONLY GET ABOUT 80% CAPACITY BACK. EACH TIME IT GETS LESS AND LESS CAPACITY. ALSO PULL YOUR EGR COOLER AND USE A SOLUTION TO DE CARBON IT, IT PREVENTS HOT SPOTS AND PREMATURE BURN OUT. I ALSO PULL MY EGR VALVE AND CLEAN THE CARBON AND SOOT DEPOSITS FROM IT AS WELL, I PULL THE DELTA P SENSOR CLEAN IT, DEF FLUID FILTER CHANGE, DEF INJECTOR, THE 7TH INJECTOR CLEAN IT, I DO THIS IN MY DRIVEWAY AT THE HOUSE AS IT'S A FEW CLAMPS AND GASKETS AND COSTS ME ABOUT A DAY DOING ALL THIS AND SAVES ME $$$. JUST BE VERY CAREFUL REMOVING DPF FILTER DON'T DROP IT AS THE CERAMIC WILL CRACK. I USE A TRANNY JACK OR A ATV/MOTORCYCLE JACK TO REMOVE AND INSTALL FILTER. TAKES ABOUT 45 MIN TO REMOVE AND ABOUT AN HR AND A HALF TO RE INSTALL. WHOLE PROCESS NOT TO BAD IF YOU ARE MECHANICALLY INCLINED AND TAKE YOUR TIME. HOPE THIS HELPS SOMEONE. DEALER CHARGES $1500.00 BY DOING IT MY SELF I SAVE ROUGHLY $700.00.