P0401 EGR Flow Insufficient Solved
P0401 EGR Flow Insufficient Solved
Hello,
I have been struggling with a p0401 for a couple of months.
My car has been idling very bad, initially upon startup, it would idle ok, vac guage around 18in/Hg at >1000rpm. After a minute or so the idle would drop to 900rpm and my vac would go to ~10in/HG and a rough idle would occur. CES light would come on with P0401 eventually after a few driving cycles.
I changed the EGR valve even though it would open and close when I applied vacuum from an external pump, the intake manifold inlets were also clear. With the EGR valve changed out for a new one the problem persisted.
I bought an EGR vacuum solenoid valve and installed it tonight ($70 from Rock Auto). So far it seems to have fixed my problem, the car runs well and the idle is good. It idles around 900rpm at about 18"/Hg.
My car is an 04 Evo with 107,000 miles. AMS tuned with 264in/272ex HKS cams, AMS Turbo Back Exhaust and some suspension mods plus minor stuff.
The point of this thread is to help others who may have a p0401 code who are struggling to fix it. My fix was to replace the EGR vacuum solenoid valve.
I have been struggling with a p0401 for a couple of months.
My car has been idling very bad, initially upon startup, it would idle ok, vac guage around 18in/Hg at >1000rpm. After a minute or so the idle would drop to 900rpm and my vac would go to ~10in/HG and a rough idle would occur. CES light would come on with P0401 eventually after a few driving cycles.
I changed the EGR valve even though it would open and close when I applied vacuum from an external pump, the intake manifold inlets were also clear. With the EGR valve changed out for a new one the problem persisted.
I bought an EGR vacuum solenoid valve and installed it tonight ($70 from Rock Auto). So far it seems to have fixed my problem, the car runs well and the idle is good. It idles around 900rpm at about 18"/Hg.
My car is an 04 Evo with 107,000 miles. AMS tuned with 264in/272ex HKS cams, AMS Turbo Back Exhaust and some suspension mods plus minor stuff.
The point of this thread is to help others who may have a p0401 code who are struggling to fix it. My fix was to replace the EGR vacuum solenoid valve.
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Hello,
I have been struggling with a p0401 for a couple of months.
My car has been idling very bad, initially upon startup, it would idle ok, vac guage around 18in/Hg at >1000rpm. After a minute or so the idle would drop to 900rpm and my vac would go to ~10in/HG and a rough idle would occur. CES light would come on with P0401 eventually after a few driving cycles.
I changed the EGR valve even though it would open and close when I applied vacuum from an external pump, the intake manifold inlets were also clear. With the EGR valve changed out for a new one the problem persisted.
I bought an EGR vacuum solenoid valve and installed it tonight ($70 from Rock Auto). So far it seems to have fixed my problem, the car runs well and the idle is good. It idles around 900rpm at about 18"/Hg.
My car is an 04 Evo with 107,000 miles. AMS tuned with 264in/272ex HKS cams, AMS Turbo Back Exhaust and some suspension mods plus minor stuff.
The point of this thread is to help others who may have a p0401 code who are struggling to fix it. My fix was to replace the EGR vacuum solenoid valve.
I have been struggling with a p0401 for a couple of months.
My car has been idling very bad, initially upon startup, it would idle ok, vac guage around 18in/Hg at >1000rpm. After a minute or so the idle would drop to 900rpm and my vac would go to ~10in/HG and a rough idle would occur. CES light would come on with P0401 eventually after a few driving cycles.
I changed the EGR valve even though it would open and close when I applied vacuum from an external pump, the intake manifold inlets were also clear. With the EGR valve changed out for a new one the problem persisted.
I bought an EGR vacuum solenoid valve and installed it tonight ($70 from Rock Auto). So far it seems to have fixed my problem, the car runs well and the idle is good. It idles around 900rpm at about 18"/Hg.
My car is an 04 Evo with 107,000 miles. AMS tuned with 264in/272ex HKS cams, AMS Turbo Back Exhaust and some suspension mods plus minor stuff.
The point of this thread is to help others who may have a p0401 code who are struggling to fix it. My fix was to replace the EGR vacuum solenoid valve.