I have a 1994 with the 4.0L engine 4x4 and it's is continually having DPFE failures. I've replaced the sensor 5 times in the last few months, replaced the EGR solenoid, replaced the catalytic converter, replaced the hoses to the DPFE sensor,
After I replaced the DPFE sensor it will run normally for a week or so and then check engine light comes on again. My mechanic is flummoxed and has thrown his hands up in despair. Don't know what else to do.
I even shot some carb cleaner down the EGR sensor exhaust tube that the hoses connect to thinking maybe a clog in the pipe was causing the problem. Still nothing I've checked all the vacuum hoses and everything looks good.
Truck runs good except at low speed under load and then it kinda stumbles/surges? I'm unable to find a Motorcraft DPFE sensor from any dealer. I'm forced to buy aftermarket, is this the problem?
Does anyone have any idea what to do to correct this problem?