EGR's purpose?
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From: Hermosa Beach, CA
EGR's purpose?
Anybody know the answer to this? I'm having issues that seem to be pointing to the EGR valve/sensor/etc. I don't want to replace everything and have heard to just remove everything. I'm cool with that, but I don't even know what it's for in the first place.
What does EGR stand for? Thanks for any help.
BD
What does EGR stand for? Thanks for any help.BD
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From: Nashville
I'm not 100% sure, but I'll try to answer the question.
EGR = exhaust gas recirculation
It lowers the cylinder temperatures by allowing already burnt gases to take up space. I think it also reburns some gasses which haven't been burnt therefore producing a cleaner exhaust.
EGR = exhaust gas recirculation
It lowers the cylinder temperatures by allowing already burnt gases to take up space. I think it also reburns some gasses which haven't been burnt therefore producing a cleaner exhaust.
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From: Selden NY
You know I wanted to ask the same thing today.
I've been reading a decent amount of post lately where people
had problems (mostly Idle issues) and totally disconnected the EGR system and problems went away.
Would love to see a "HOW TO" on exactly what we are disconnecting and is there a prob as a result, example:
passing an inspection ?
I've been reading a decent amount of post lately where people
had problems (mostly Idle issues) and totally disconnected the EGR system and problems went away.
Would love to see a "HOW TO" on exactly what we are disconnecting and is there a prob as a result, example:
passing an inspection ?
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Senior Member
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From: Hermosa Beach, CA
Rock on. No worries then. The EPA ain't worth 250 bucks to replace the assembly
No wonder I never had one on my 74 Charger.......Ah the simple days.
BD
No worries there either Rob. I just passed yesterday so I'm good for 3 years
No wonder I never had one on my 74 Charger.......Ah the simple days.BD
No worries there either Rob. I just passed yesterday so I'm good for 3 years
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From: Miami, FL
Originally posted by Rob_02Lightning
You know I wanted to ask the same thing today.
I've been reading a decent amount of post lately where people
had problems (mostly Idle issues) and totally disconnected the EGR system and problems went away.
Would love to see a "HOW TO" on exactly what we are disconnecting and is there a prob as a result, example:
passing an inspection ?
You know I wanted to ask the same thing today.
I've been reading a decent amount of post lately where people
had problems (mostly Idle issues) and totally disconnected the EGR system and problems went away.
Would love to see a "HOW TO" on exactly what we are disconnecting and is there a prob as a result, example:
passing an inspection ?
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From: Richmond, VA, USA
there's a little more to it than just unplugging a vacuum line.
there is a sensor called the dpfe that makes sure the egr system is functioning properly.
if the dpfe sees no egr flow when the pcm commands it, then the egr sets a code and turns on the check engine light.
I believe that the pcm also makes timing adjustments to correspond with egr flow.
if you are removing the egr for performance gains (aside from heat transfer to the upper intake) then you are wasting your time.
if you are removing the egr because it's malfunctioning and you don't want to spend the time or money fixing it, then I understand.
if you are removing the egr to "clean up" the look of the engine bay, then I understand that too, but you should also go ahead and remove the dpfe sensor, the evr solenoid, the egr valve and tube, and the vacuum lines.
in any event, you need to have the system turned off completely via tuning.
just my .02
later,
chris
there is a sensor called the dpfe that makes sure the egr system is functioning properly.
if the dpfe sees no egr flow when the pcm commands it, then the egr sets a code and turns on the check engine light.
I believe that the pcm also makes timing adjustments to correspond with egr flow.
if you are removing the egr for performance gains (aside from heat transfer to the upper intake) then you are wasting your time.
if you are removing the egr because it's malfunctioning and you don't want to spend the time or money fixing it, then I understand.
if you are removing the egr to "clean up" the look of the engine bay, then I understand that too, but you should also go ahead and remove the dpfe sensor, the evr solenoid, the egr valve and tube, and the vacuum lines.
in any event, you need to have the system turned off completely via tuning.
just my .02
later,
chris
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From: NW
Most of the time when the EGR system starts to malfunction it's caused by one of the sensors that controll the valve.
Disconnecting the vacume line to the diaphram is the easiest way to disable it.
However, if your having a problem with the valve itself ....... such as it's stuck open or not closing completely ....... then simply disconnecting the line will not fix the problem. A block off plate will be the way to go then.
It's rare that the valve itself malfunctions, so more than likely just disconnecting the vacume line will be the way to go.
Most Ford run better with the system disabled even if it's working properly. It's not so noticeable with an automatic, but you can definatley tell the difference in a stick shift when you disable the system.
Disconnecting the vacume line to the diaphram is the easiest way to disable it.
However, if your having a problem with the valve itself ....... such as it's stuck open or not closing completely ....... then simply disconnecting the line will not fix the problem. A block off plate will be the way to go then.
It's rare that the valve itself malfunctions, so more than likely just disconnecting the vacume line will be the way to go.
Most Ford run better with the system disabled even if it's working properly. It's not so noticeable with an automatic, but you can definatley tell the difference in a stick shift when you disable the system.
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From: Chicago, Illinois
No one's mentioned it yet, so for my .02, one of the main purposes of the EGR system IS environmental, but not to make exhaust cleaner. At low power need levels (ie. highway cruising speeds), exhaust is pumped into the cylinders to effectively reduce combustion cylinder volume, saving a ton of gas consumption in the process. That's mainly why engines get higher fuel mileage on the highway (along with overdrive gears, etc., I know).
If that 1-2 extra MPG doesn't mean much to you, go for ripping it all out!
If that 1-2 extra MPG doesn't mean much to you, go for ripping it all out!
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From: Richmond, VA, USA
here's a little more information on the EGR system and how it works, directly from our friends at Ford!
Exhaust Gas Recirculation Systems
Overview
The Exhaust Gas Recirculation (EGR) system controls the oxides of nitrogen (NOx) emissions. Small amounts of exhaust gases are recirculated back into the combustion chamber to mix with the air/fuel charge. The combustion chamber temperature is reduced, lowering NOx emissions.
Differential Pressure Feedback EGR System
The Differential Pressure Feedback EGR system consists of a differential pressure feedback EGR sensor, EGR vacuum regulator solenoid, EGR valve, orifice tube assembly, powertrain control module (PCM) and connecting wires and vacuum hoses. Operation of the system is as follows (see attached illustration):
1. Signals from the engine coolant temperature (ECT) sensor, intake air temperature (IAT) sensor, throttle position (TP) sensor, mass air flow (MAF) sensor and crankshaft position (CKP) sensor provide information on engine operating conditions to the PCM. The engine must be warm, stable and running at a moderate load and rpm before the EGR system is activated. The PCM deactivates EGR during idle, extended wide open throttle or whenever a failure is detected in an EGR component or EGR required input.
2. The PCM calculates the desired amount of EGR flow for a given engine condition. It then determines the desired pressure drop across the metering orifice required to achieve that flow and outputs the corresponding signal to the EGR vacuum regulator solenoid.
3. The EGR vacuum regulator solenoid receives a variable duty cycle signal (0 to 100%). The higher the duty cycle the more vacuum the solenoid diverts to the EGR valve.
4. The increase in vacuum acting on the EGR valve diaphragm overcomes the valve spring and begins to lift the EGR valve pintle off its seat, causing exhaust gas to flow into the intake manifold.
5. Exhaust gas flowing through the EGR valve must first pass through the EGR metering orifice. With one side of the orifice exposed to exhaust backpressure and the other to the intake manifold, a pressure drop is created across the orifice whenever there is EGR flow. When the EGR valve closes, there is no longer flow across the metering orifice and pressure on both sides of the orifice is the same. The PCM constantly targets a desired pressure drop across the metering orifice to achieve the desired EGR flow.
6. The differential pressure feedback EGR sensor measures the actual pressure drop across the metering orifice and relays a proportional voltage signal (0 to 5 volts) to the PCM. The PCM uses this feedback signal to correct for any errors in achieving the desired EGR flow.
Overview
The Exhaust Gas Recirculation (EGR) system controls the oxides of nitrogen (NOx) emissions. Small amounts of exhaust gases are recirculated back into the combustion chamber to mix with the air/fuel charge. The combustion chamber temperature is reduced, lowering NOx emissions.
Differential Pressure Feedback EGR System
The Differential Pressure Feedback EGR system consists of a differential pressure feedback EGR sensor, EGR vacuum regulator solenoid, EGR valve, orifice tube assembly, powertrain control module (PCM) and connecting wires and vacuum hoses. Operation of the system is as follows (see attached illustration):
1. Signals from the engine coolant temperature (ECT) sensor, intake air temperature (IAT) sensor, throttle position (TP) sensor, mass air flow (MAF) sensor and crankshaft position (CKP) sensor provide information on engine operating conditions to the PCM. The engine must be warm, stable and running at a moderate load and rpm before the EGR system is activated. The PCM deactivates EGR during idle, extended wide open throttle or whenever a failure is detected in an EGR component or EGR required input.
2. The PCM calculates the desired amount of EGR flow for a given engine condition. It then determines the desired pressure drop across the metering orifice required to achieve that flow and outputs the corresponding signal to the EGR vacuum regulator solenoid.
3. The EGR vacuum regulator solenoid receives a variable duty cycle signal (0 to 100%). The higher the duty cycle the more vacuum the solenoid diverts to the EGR valve.
4. The increase in vacuum acting on the EGR valve diaphragm overcomes the valve spring and begins to lift the EGR valve pintle off its seat, causing exhaust gas to flow into the intake manifold.
5. Exhaust gas flowing through the EGR valve must first pass through the EGR metering orifice. With one side of the orifice exposed to exhaust backpressure and the other to the intake manifold, a pressure drop is created across the orifice whenever there is EGR flow. When the EGR valve closes, there is no longer flow across the metering orifice and pressure on both sides of the orifice is the same. The PCM constantly targets a desired pressure drop across the metering orifice to achieve the desired EGR flow.
6. The differential pressure feedback EGR sensor measures the actual pressure drop across the metering orifice and relays a proportional voltage signal (0 to 5 volts) to the PCM. The PCM uses this feedback signal to correct for any errors in achieving the desired EGR flow.
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From: NW
One more thing, if you do take off everything that Superfords mentioned including the bracket that holds all that stuff on ...........
You'll free up alot of room on the driver side, and that will make changing the plugs WAY more easy.
You'll free up alot of room on the driver side, and that will make changing the plugs WAY more easy.
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From: Richmond, VA, USA
Originally posted by Cali L
When you take everything off, what do you need to block any open orifices so to speak? I'm ready to do this, but would like input on what's needed before I start.
BD
When you take everything off, what do you need to block any open orifices so to speak? I'm ready to do this, but would like input on what's needed before I start.
BD
when you remove the EGR valve, there will be a hole on the side of the upper intake plenum that you will need to block off. you'll need to purchase or have a simple plate made that will bolt on in place of the valve to cover this hole. if you don't block this off you'll have a helluva vacuum leak.
you'll need to cap off the threaded fitting on your driver side header or manifold that would attach to the bottom end of the large metal tube that delivers exhaust gas up to the egr valve itself. some people have used the existing fitting that is made onto the end of the tube that you are removing, and simply cut the metal tube, removed it, put a quarter in the fitting and screwed it back on. low tech but effective. there is also a standard cap that you can probably buy at lowes for not much more than that quarter that will cap off the hole nicely. do a search, or somebody may chime in with the correct thread and size. if you don't block this opening off, you'll have a helluva exhaust leak.
you'll need to close off or block the vacuum supply line that goes from the intake manifold to the EVR solenoid or egr vacuum regulator. it is the line that has vacuum at all times, not the line that goes from the evr to the top of the egr valve itself. if you don't block this line off you'll have a vacuum leak.
there are also a few variations that you could do. example being, leaving the equipment installed, thus eliminating the need to block things off, but still disabling the system.
good luck
law breakers.
j/klater,
chris
Last edited by superfords; Jul 16, 2004 at 09:41 PM.
