Hmmmmm, the p401 has returned again........checked the exhaust passage from the EGR valve into the intake manifold. Cleaned it out in case a lump of carbon had gotten stuck in the channel. Nope no luck there, checked vacumm to the EGR, it was there, put vacumm on the EGR manually, yep working, motor started running rough but not stalling. Hmmm, checked the old hoses to the DPFE, look good to me. I'm guessing the DPFE, yet again. This will be my 4th unit. 01V6 base 216k miles. Runs great, paint great, some wear on drivers leather seat. Everything else works as it should.