Code p405
 

Have a code p405. I replaced the egr last year and notice the wiring was melted. Fixed the wiring and several months later the check engine light return with p405. Wires melted again. Retired again tonight and erased code but would not erase, unhooked battery and code erased for a while. Engine light p405 again. My question is when the wires short when melting from engine heat, will it short out the DPFE sensor by short circuit. This is on a 2006 explorer.
Thanks