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Next: 89T hesitates revving, loses power at low speed
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External
Since: Apr 28, 2005
Posts: 12
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(Msg. 1) Posted: Thu Jul 07, 2005 10:15 am
Post subject: EGR P0401 - Exhaust Gas Recirculation Flow Insufficient
Archived from groups: alt>autos>gm (more info?)
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Hi,
I have a 1996 Chevy Lumna sedan with 130.000 miles. The engine light is
on and my scanner reades P0401. All othere checks are ok.
The car runs fine. Some causes could be excessive backpressure. How
do I check for that? Any way I can check the EGR valve incase that is
the problem? A new one cost $160 and it is too expensive to take the
shotgun approach. Any ideas would be appreciated. The car is due for
it's state inspection in August.
Thanks,
Ed |
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External
Since: Jan 17, 2004
Posts: 202
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(Msg. 2) Posted: Thu Jul 07, 2005 1:32 pm
Post subject: Re: EGR P0401 - Exhaust Gas Recirculation Flow Insufficient [Login to view extended thread Info.]
Archived from groups: per prev. post (more info?)
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Your MAP sensor is also a suspect for your code. A reduction of manifold
pressure as sensed by the MAP sensor is how the computer figures out there
is sufficient EGR flow when it runs the test.
"Ed" <edgossjbs.RemoveThis@verizon.net> wrote in message
news:1120756504.786830.271270@g14g2000cwa.googlegroups.com...
> Hi,
>
> I have a 1996 Chevy Lumna sedan with 130.000 miles. The engine light is
> on and my scanner reades P0401. All othere checks are ok.
>
> The car runs fine. Some causes could be excessive backpressure. How
> do I check for that? Any way I can check the EGR valve incase that is
> the problem? A new one cost $160 and it is too expensive to take the
> shotgun approach. Any ideas would be appreciated. The car is due for
> it's state inspection in August.
>
> Thanks,
> Ed
> |
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External
Since: Apr 28, 2005
Posts: 12
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(Msg. 3) Posted: Thu Jul 07, 2005 1:56 pm
Post subject: Re: EGR P0401 - Exhaust Gas Recirculation Flow Insufficient [Login to view extended thread Info.]
Archived from groups: per prev. post (more info?)
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External
Since: Apr 28, 2005
Posts: 12
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(Msg. 4) Posted: Thu Jul 07, 2005 3:23 pm
Post subject: Re: EGR P0401 - Exhaust Gas Recirculation Flow Insufficient [Login to view extended thread Info.]
Archived from groups: per prev. post (more info?)
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External
Since: Jul 06, 2005
Posts: 13
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(Msg. 5) Posted: Thu Jul 07, 2005 5:23 pm
Post subject: Re: EGR P0401 - Exhaust Gas Recirculation Flow Insufficient [Login to view extended thread Info.]
Imported from groups: per prev. post (more info?)
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External
Since: Feb 12, 2005
Posts: 17
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(Msg. 6) Posted: Thu Jul 07, 2005 6:53 pm
Post subject: Re: EGR P0401 - Exhaust Gas Recirculation Flow Insufficient [Login to view extended thread Info.]
Archived from groups: per prev. post (more info?)
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Ed wrote:
> Hi,
>
> I have a 1996 Chevy Lumna sedan with 130.000 miles. The engine light is
> on and my scanner reades P0401. All othere checks are ok.
>
> The car runs fine. Some causes could be excessive backpressure. How
> do I check for that? Any way I can check the EGR valve incase that is
> the problem? A new one cost $160 and it is too expensive to take the
> shotgun approach. Any ideas would be appreciated. The car is due for
> it's state inspection in August.
>
> Thanks,
> Ed
My wife's Impala gave that code and it turned out to just be a dirty air
filter. >> Stay informed about: EGR P0401 - Exhaust Gas Recirculation Flow Insufficient |
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External
Since: Jul 06, 2005
Posts: 13
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(Msg. 7) Posted: Thu Jul 07, 2005 9:46 pm
Post subject: Re: EGR P0401 - Exhaust Gas Recirculation Flow Insufficient [Login to view extended thread Info.]
Imported from groups: per prev. post (more info?)
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External
Since: Apr 28, 2005
Posts: 12
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(Msg. 8) Posted: Fri Jul 08, 2005 6:03 am
Post subject: Re: EGR P0401 - Exhaust Gas Recirculation Flow Insufficient [Login to view extended thread Info.]
Archived from groups: per prev. post (more info?)
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External
Since: Jul 06, 2005
Posts: 13
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(Msg. 9) Posted: Fri Jul 08, 2005 1:45 pm
Post subject: Re: EGR P0401 - Exhaust Gas Recirculation Flow Insufficient [Login to view extended thread Info.]
Imported from groups: per prev. post (more info?)
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External
Since: Apr 28, 2005
Posts: 12
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(Msg. 10) Posted: Fri Jul 08, 2005 4:58 pm
Post subject: Re: EGR P0401 - Exhaust Gas Recirculation Flow Insufficient [Login to view extended thread Info.]
Archived from groups: per prev. post (more info?)
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External
Since: Apr 28, 2005
Posts: 12
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(Msg. 11) Posted: Fri Jul 08, 2005 8:01 pm
Post subject: Re: EGR P0401 - Exhaust Gas Recirculation Flow Insufficient [Login to view extended thread Info.]
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External
Since: Jul 06, 2005
Posts: 13
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(Msg. 12) Posted: Fri Jul 08, 2005 9:58 pm
Post subject: Re: EGR P0401 - Exhaust Gas Recirculation Flow Insufficient [Login to view extended thread Info.]
Imported from groups: per prev. post (more info?)
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External
Since: Apr 28, 2005
Posts: 12
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(Msg. 13) Posted: Sat Jul 09, 2005 9:23 am
Post subject: Re: EGR P0401 - Exhaust Gas Recirculation Flow Insufficient [Login to view extended thread Info.]
Archived from groups: per prev. post (more info?)
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Here is what I tried today;
*Remove EGR clean exhaust pipe to manifold and clean inside valve. It
didn't look bad. Very little carbon.
*Ran car at idle was fine. Took it down the road up to about 35 mph and
light came back on P0401
*Car at operating temp.
*Removed Linear EGR valve, but left wired.
*Started car. Idled a little rough until I plugged the intake manafold
port.
*I reved the engine while observing the EGR valve. It never opened up
even after I plugged the intake port.
I know on the old vacuum ones that they opened when reving the engine.
My manual does not have any electrical checks to do on the EGR. Does
this mean PCM or MAP could be the problem. MAP monitors the vacuum.
Thanks >> Stay informed about: EGR P0401 - Exhaust Gas Recirculation Flow Insufficient |
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External
Since: Jul 06, 2005
Posts: 13
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(Msg. 14) Posted: Sat Jul 09, 2005 1:34 pm
Post subject: Re: EGR P0401 - Exhaust Gas Recirculation Flow Insufficient [Login to view extended thread Info.]
Imported from groups: per prev. post (more info?)
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External
Since: Aug 05, 2004
Posts: 158
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(Msg. 15) Posted: Sat Jul 09, 2005 10:02 pm
Post subject: Re: EGR P0401 - Exhaust Gas Recirculation Flow Insufficient [Login to view extended thread Info.]
Archived from groups: per prev. post (more info?)
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It will open when engine is at operating temperature and engine speed is
above idle. If the EGR was not opening when the PCM commanded it to, you
should get a P0406 as well as a P0401.
Now, for the 1996 model year W car with the 3100 engine there is a TSB
(87-65-22, August 1998) where the MIL comes on because the EGR flow test
fails because the expected change in manifold pressure falls outside the
calibrated window during deceleration.
The correction to this is having the PROM reprogrammed by the dealer.
Steve
"Ed" <edgossjbs RemoveThis @verizon.net> wrote in message
news:1120926200.070873.95670@g43g2000cwa.googlegroups.com...
> Here is what I tried today;
>
> *Remove EGR clean exhaust pipe to manifold and clean inside valve. It
> didn't look bad. Very little carbon.
> *Ran car at idle was fine. Took it down the road up to about 35 mph and
> light came back on P0401
> *Car at operating temp.
> *Removed Linear EGR valve, but left wired.
> *Started car. Idled a little rough until I plugged the intake manafold
> port.
> *I reved the engine while observing the EGR valve. It never opened up
> even after I plugged the intake port.
>
> I know on the old vacuum ones that they opened when reving the engine.
>
> My manual does not have any electrical checks to do on the EGR. Does
> this mean PCM or MAP could be the problem. MAP monitors the vacuum.
>
> Thanks
> >> Stay informed about: EGR P0401 - Exhaust Gas Recirculation Flow Insufficient |
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