Code p0402

[Connor469]

I'm new to the explorer world. Just bought a 1996 302 awd. It's got 139,x.. miles on it. I hooked up my scanner to it and it had code p0402 (egr flow excessive) so I decided to replace the egr valve and the egr vacuum solenoid in hope to get rid of the code. Hooked my scanner back up and erased the code. Drove it a few miles and the CEL came back on. When I got home checked for codes and p0402 was back. I am in need of desperate help because I need to take the vehicle to get inspected. Thanks in advance for everything

 

[jremington59]

OK, you have what's called the internal EGR. That means you have no EGR tube or DPFE sensor. You said you replaced the EGR valve with a new one? My next question is did you replace the sensor that bolts onto the EGR valve itself? And was there a gasket between the EGR valve and the sensor? We'll get this one fixed quick.

 

[Connor469]

No I did not replace that sensor. For some reason, this morning that code went away. Now I have code P1400. Any idea on that?

 

[jremington59]

You have a 96, 5.0, V8, awd correct?

 

[Connor469]

Yes that is correct

 

[jremington59]

The 1400 code is for low voltage to the DPFE but you don't have one. Or you shouldn't if it's a 96 engine. Does your egr valve bolt onto the back side of the engine?

 

[Connor469]

That's what I thought from looking at other threads on here. Yes, it's on the back by the firewall.

 

[jremington59]

One last question. On the passenger exhaust manifold, is there a steel tube running from the manifold to the EGR valve?

 

[Connor469]

No there is not.

 

[jremington59]

OK, so you have the internal egr system. I have no idea why you're showing a code for low voltage to the DPFE that you don't have. When you changed the EGR valve, did you take the sensor off the old one and put it on the new EGR valve before reinstalling it? And if so was there a gasket between the egr valve and the sensor?

 

[Connor469]

Yes I did move the sensor onto the new one. If I remember correctly it did have a gasket

 

[jremington59]

That sensor, if I recall does the same thing that the DPFE does on a regular EGR system. You most likely didn't have a bad EGR valve to begin with. It very seldom is. I'm guessing that the sensor connecting to the EGR valve is bad or you have a bad electrical connection. Check the hoses real good but I imagine the vacuum is good if it's pulling the EGR valve open for excessive flow. I believe that sensor is around 25 dollars. There's only one other thing and that would be the black piece the two hoses connect to, but I can't recall the name. It might be called the vacuum regulator. Id take off the EGR valve and return it. It was a new EGR valve right? When you get EGR parts for this one remember to tell them you have the PFE system, not the DPFE system.

 

[Connor469]

Yes it was a new egr valve. I think you are referring to the vacuum solenoid, that is the black thing that the two hoses connect to. I replaced that when I replaced the egr valve. I will check all electrical connections and if that doesn't work I will get a new position sensor. I will let you know how it goes. Thank you for your help!

 

[jremington59]

I'm quite sure that sensor is the problem. Make sure it comes with a new gasket, and good luck....

 

[Connor469]

Replaced the sensor and no more codes! Thank you!

 

[jremington59]

Glad to hear. Thx for following up.