Big thanks to all on this site for sharing their knowledge and experience. My SES lite came on my 2000 5.4 once this winter and again last week. It went out both times after a day or so. I bought a code reader and pulled code P1405. The definition is DPFE sensor upstream hose off or plugged. So I searched all posts on this site for that code and other related words. Got alot of good advice and experience. Today I looked real close at the hoses to the DPFE sensor, and sure enough, the hose was cracked open right where it is squeezed onto the sensor. Ford uses a 1\4 inch diameter ID hose and stretches it to fit over the 5\16 fitting ends. So it is prone to crack where the "stretch mark" is. The other hose to the DPFsensor has 1\4 fittings so that hose on mine was fine. Now I am off to the dealership or parts store to buy 2 feet of good 1\4 emission hose to replace both hoses. I am sure if I took it into a dealership to repair the code they would have replaced the DPFsensor for hundreds of bucks (the sensor sells for 146.00 here in Canada, but 72 bucks online at galaxy.parts aka Burd Ford in Indiana. I have bought stuff from Galaxy before and got great service and best prices) Thanks again guys.

 

For those looking for new hose between the DPFE sensor and the exhaust tube, ford carries it as part no. 1L3Z9P761BA ( Hose AS 09A0). Big price at 14 bucks a foot here in Canada, You US guys will get if for half that. It is special emissions hose. It is much, much, better than 1\4 ID fuel hose that someone at the aftermarket parts store was trying to sell me. The above part number is for the larger of the 2 hoses, the upstream side. They showed me the hose for the other port on the sensor, it is visibly smaller in diameter. This hose takes alot of heat, and mine cracked where the heat had broken the inside apart.