egr system not working

[ahmos]

The egr system of my explorer is not working .
I checked the dpfe and its ok
I disconnected the dpfe cable and wires but I get no cel , drove the car with the wires not connected and no cel (check engine light)
so what causing the problem ... is it the pcm or a bad ground wire or what ?

 

[Turdle]

Probably a stupid question, but does the Check engine light turn on when you turn the key to the on position?

Ok, another
Is there by chance a custom tune file installed in your explorer? do you have a black box tuner ( xcal)?

What is your location? is this a US built explorer? Which engine does your Explorer have?

 

[ahmos]

Yes the cel comes on when I turn the key on and then go away
There is no modification to this car and no costume tune .. the only modification is xenon light
This car is a US product and the engine is 4.0L sohc explorer xlt 98
I noticed also when I disconnected the wires of the maf sensor the cel didn't come on but the Max is working as soon as I connect it again.. and I don't know if it has a similar issue like the egr or not

 

[2000StreetRod]

not working determination?

If the CEL doesn't come on how did you determine that the EGR is not working? See EGR System O&T

 

[ahmos]

I checked every part as in the post and its all working
But
I connected a vacuum line to the evr from where it goes to the egr but I feel no vacuum coming even when driving and accelerating I connected a vacuum gauge but it reads nothing
And I read another post that it should give me up to 5 in-hg
So I only think that the pcm dont activate the system for another reason

 

[2000StreetRod]

vacuum connection?

. . . I connected a vacuum line to the evr from where it goes to the egr but I feel no vacuum coming even when driving and accelerating I connected a vacuum gauge but it reads nothing . . .

Did you use a "T" so the connection between the EVR and EGR valve was maintained? If you just disconnected the hose to the EGR valve and connected it to the gauge the PCM may have determined that the EGR valve was not functioning and disabled EGR until the next drive cycle.