Code P0401 Insufficient Exhaust Gas Flow

I have 96 explorer 4wd 4.0 engine with 70k miles. hastily replaced egr
valve and reset code but code came back after 2nd start. getting very
week vacuum at the vacuum supply hose (less than 1" i believe). zero
voltage read at EVR Solenoid power supply but i'm not sure if i should
be getting 12v signal with engine hot and normal idle. supplying 12 vdc
doesnt seem to affect airflow through solenoid. any advice would be
appreciated. TIA

Usual culprit is DPFE... don't stick your finger over the vacuum hose
checking for vacuum... you're going to feel a "nibble" because the EVRV is
duty cycled. Not sure how you are checking the electrical side of the
EVRV... these have 12 volts supplied as long as the key is on... PCM
switches the ground side of the solenoid.


"Spud Unger" > wrote in message
...
> I have 96 explorer 4wd 4.0 engine with 70k miles. hastily replaced egr
> valve and reset code but code came back after 2nd start. getting very
> week vacuum at the vacuum supply hose (less than 1" i believe). zero
> voltage read at EVR Solenoid power supply but i'm not sure if i should
> be getting 12v signal with engine hot and normal idle. supplying 12 vdc
> doesnt seem to affect airflow through solenoid. any advice would be
> appreciated. TIA

It's good to have you here helping out with these types of problems, Jim.

Bob


"Jim Warman" > wrote in message
news:Zi2Ae.104733$HI.30501@edtnps84...
> Usual culprit is DPFE... don't stick your finger over the vacuum hose
> checking for vacuum... you're going to feel a "nibble" because the EVRV is
> duty cycled. Not sure how you are checking the electrical side of the
> EVRV... these have 12 volts supplied as long as the key is on... PCM
> switches the ground side of the solenoid.
>
>
> "Spud Unger" > wrote in message
> ...
>> I have 96 explorer 4wd 4.0 engine with 70k miles. hastily replaced egr
>> valve and reset code but code came back after 2nd start. getting very
>> week vacuum at the vacuum supply hose (less than 1" i believe). zero
>> voltage read at EVR Solenoid power supply but i'm not sure if i should
>> be getting 12v signal with engine hot and normal idle. supplying 12 vdc
>> doesnt seem to affect airflow through solenoid. any advice would be
>> appreciated. TIA
>
>

Thanx, Bob... there's lot's of times I come across sounding like a real
dick....truth of the matter is.... I'm a real dick. Just doing my part to
show that all techs aren't stupid nor thieves...


"Bob" > wrote in message
nk.net...
> It's good to have you here helping out with these types of problems, Jim.
>
> Bob
>
>
> "Jim Warman" > wrote in message
> news:Zi2Ae.104733$HI.30501@edtnps84...
> > Usual culprit is DPFE... don't stick your finger over the vacuum hose
> > checking for vacuum... you're going to feel a "nibble" because the EVRV
is
> > duty cycled. Not sure how you are checking the electrical side of the
> > EVRV... these have 12 volts supplied as long as the key is on... PCM
> > switches the ground side of the solenoid.
> >
> >
> > "Spud Unger" > wrote in message
> > ...
> >> I have 96 explorer 4wd 4.0 engine with 70k miles. hastily replaced egr
> >> valve and reset code but code came back after 2nd start. getting very
> >> week vacuum at the vacuum supply hose (less than 1" i believe). zero
> >> voltage read at EVR Solenoid power supply but i'm not sure if i should
> >> be getting 12v signal with engine hot and normal idle. supplying 12 vdc
> >> doesnt seem to affect airflow through solenoid. any advice would be
> >> appreciated. TIA
> >
> >
>
>

i was checking power supply to the solenoid with a dvm with the engine
hot and running. it showed 0 volts dc. dpfe seems to be consensus on
most of the forums i've checked. thanks for response.

Jim Warman wrote:
> Usual culprit is DPFE... don't stick your finger over the vacuum hose
> checking for vacuum... you're going to feel a "nibble" because the EVRV is
> duty cycled. Not sure how you are checking the electrical side of the
> EVRV... these have 12 volts supplied as long as the key is on... PCM
> switches the ground side of the solenoid.
>
>
> "Spud Unger" > wrote in message
> ...
>
>>I have 96 explorer 4wd 4.0 engine with 70k miles. hastily replaced egr
>>valve and reset code but code came back after 2nd start. getting very
>>week vacuum at the vacuum supply hose (less than 1" i believe). zero
>>voltage read at EVR Solenoid power supply but i'm not sure if i should
>>be getting 12v signal with engine hot and normal idle. supplying 12 vdc
>>doesnt seem to affect airflow through solenoid. any advice would be
>>appreciated. TIA
>
>
>

Jim Warman wrote:
> Usual culprit is DPFE... don't stick your finger over the vacuum hose
> checking for vacuum... you're going to feel a "nibble" because the EVRV is
> duty cycled. Not sure how you are checking the electrical side of the
> EVRV... these have 12 volts supplied as long as the key is on... PCM
> switches the ground side of the solenoid.
>
>
> "Spud Unger" > wrote in message
> ...
>
>>I have 96 explorer 4wd 4.0 engine with 70k miles. hastily replaced egr
>>valve and reset code but code came back after 2nd start. getting very
>>week vacuum at the vacuum supply hose (less than 1" i believe). zero
>>voltage read at EVR Solenoid power supply but i'm not sure if i should
>>be getting 12v signal with engine hot and normal idle. supplying 12 vdc
>>doesnt seem to affect airflow through solenoid. any advice would be
>>appreciated. TIA
>
>
>
i replaced the DPFE $65 at NAPA. seems to have solved the problem. Check
Engine light has not returned after several starts. thanks for advice.