EGR excessive / rough idle
While idling:
Pull the vacuum hose of off the EGR valve.
If the idle smooths out you now know that the EGR valve is not stuck open. Put the hose back on.
Unplug the electrical connector from the EGR EVR (between the coil pack and the IAC). If the idle smooths out the DPFE is at fault, if not, the EVR is leaking.
I would not replace the DPFE without fixing the cat problem as this will be hard on it.
You can temporarily remove and plug the EGR valve vacuum hose although this can cause pinging. Use the best gas available to help mitigate.
And replace that O2, the top one behind the engine.
