DPFE Sensor Warranty Extension

I'm getting a code 327 on my 94 Ranger 4.0L V6. I'm thinking it's the DPFE sensor as the EGR valve solenoid checks out ok. The DPFE sensor has never been replaced before, and I've seen a few posts Ford having extended a warranty on this item until 2005... anyone have the details? Would it cover my '94? Does Ford have to install it?

Thanks,
Raymond