I've been posting here the last couple of weeks pertaining to a bit of pinging I was getting on my 2000 3.0 Ranger. I replaced the plugs, plug wires, and coil, as I did not know of any prior maintenance that was done on this truck before I bought it 6 months earlier. Pinging went away.
At the same time I did the major tuneup, I also replaced the DPFE with an aftermarket one, as I also figured that perhaps not enough exhaust gas was being circulated into the cylinders to help cool them down, leading to the pinging. After 10 minutes of driving with this new DPFE module, I got a CEL "P0402" excessive EGR exhaust gas code. I reset the code, drove again, and within minutes, the code reappeared.
I installed the original FoMoCo DPFE module (stamped on the back of the part), and the code has not reappeared. Here is a good link for testing your DPFE before you replace it:
Just posting this to others to be careful in buying cheap aftermarket replacement sensors. Sometimes it's best to buy the good stuff at a slightly higher price.