I have a persistant check engine light that says the dpfe sensor is out of range. I replaced the egr valve, went through the haynes manual checking voltages etc. and the conclusion was the sensor was bad. I dropped the (ouch) $150 for the new sensor, put it in and the light still comes on. I had the battery disconnected for about a half hour when I was putting in the sensor. My understanding is that should have cleared the codes. Any ideas? Thanks foryour help.