DPFE Sensor
 

I have code P401 and I have replaced this sensor 3 times in the last 1.5 yrs. Why does this sensor go bad? What are the causes? I have also replaced the oxyegen sensors as well so I know its not due to those. What else is there any ideas? Thanks

Are you using the sensor from Ford?

I think what caused the original ones were that they were aluminum and they would corrode... if I remember right! It's been a while since I put one on my old truck. The replacements were plastic and I never had a problem after changing them over on either mine or my dad's trucks.

O`Rieleys Brand and it is plastic. Is there a big difference between aftermarket and factory with these?

i have the same problem once about every 6 months its goes bad. i have searched everywhere to find out why and nothing i just think ford made a terrialbe product this time and now we all have to pay for it. but if anyone does find out how to stop them from going bad please tell me

I bought one from the Dealer this time around and for $80. bucks it better last for longer then 6 months. I wonder if running E10 has anything to do with it going bad?? I dont think I started having to replace it when I was running regular gas.

All DPFE's lead a hard life because they are exposed to elevated temperatures and lots of carbon and condensation from the exhaust gasses. Sometimes sooty water will pour out when the sensor is disconnected from its hoses. Unfortunately, with a DPFE, failure is more or less just a matter of time.

The original part installed at the factory for your era Ranger was made by Kavlico and it can have a fairly short service life. Aftermarket replacements are often worse.

The Motorola DPFE's used on some other year Rangers were much more reliable than the Kavlicos. I don't know if you can get the Motorola part in the correct configuration for the 01~03's but it would be the best bet.

CHECK THE 2 HOSES GOING TO THE DPFE SENSOR TOO, REPLACE IF BAD, ALSO IF THE EGR PORTS ARE A LITTLE CLOGGED IT WILL GIVE THE CODE TOO,ANOTHER COMMON PROBLEM WITH FORDS.. AND FINALLY TEST YOUR EGR VALVE MAKE SURE ITS GOOD