The DPFE sensor isn't supposed to melt. Yours melted because excessive hot exhaust gases got into it.

That likely happened because the Restriction Orifice in the EGR tube is clogged with soot/carbon.

Your DPFE sensor has 2 small tubes going to it and they're connected to the larger EGR tube. (the pipe that goes from the EGR valve to the exhaust manifold)

In between where each DPFE sensor tube is connected to the larger EGR tube, inside the EGR tube, there's a Restriction Orifice.

It looks like this and you can see where the 2 tubes from the DPFE sensor attach, and in between those 2 attachments, (inside the EGR Tube) is the aforementioned  Restriction Orifice.

The DPFE sensor has 2 "inlets" which connect (by small tubes) to each side of that Restriction Orifice in the EGR tube and as the intake vacuum pulls exhaust from the exhaust manifold through the open EGR Valve a pressure difference is created on each side of the Restriction Orifice and the DPFE sensor converts that value to voltage and the computer uses the voltage signal to determine how much volume of exhaust gasses are being recirculated into the intake manifold and adjusts the air/fuel mixture accordingly.

Also, the recirculated exhaust gasses serve to lower combustion temperatures as well as reduce pollution.

So if you decide to change the EGR tube you'll have to take off the EGR valve and it would be a good time to watch some youtubes on how to clean and test it while you have if off.

So here's what the setup looks like.

Look at the sensor and see if it’s clean and new. Make sure they replaced it. I’ve seen shops charge for new parts and install crap they pulled of wrecked vehicles. If you go to any shop for repairs always ask for you old parts back.