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· Life Ruiner
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4,868 Posts
Discussion Starter · #1 ·
Searched and couldnt find anything helpful. I'm going to go through the diagnostics specified in the Legend repair manuals but CEL EGR code 12 comes on under in gear acceleration. When i shut the car off and turn it back on the CEL doesnt come on again until i accelerate a good amount again, sometimes it doesnt come on at all. This is the second sensor i've swapped with the same result. When this pin on the sensor gets pushed up by the diaphram it sends signal to the ECU, but what does it tell it? The EGR was left intact and untouched, ive never had problems with it before. Could the increase in air of the gutted manifold have anything to do with it?

Let me know your thoughts as i have to get this thing smoged by the month end and can have a CEL pop up.

Thanks,

~TRu Hybrid
 

· Registered
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2,843 Posts
There are 2 control solenoids that operate the EGR valve, one is vacuum operated, the other is electrical and is controlled by the ECU. Either of those may have failed. You can bypass the green/white vacuum controlled valve pretty easily. Quick way of narrowing it down. Cheap "fix" but whatever works. Basically you want the electric solenoid to supply vacuum directly to the EGR valve rather than through the vacuum solenoid. If this corrects the CEL, you've isolated the faulty component. You can check the electric solenoid by applying power/gnd to it and confirm that it is opening properly. Also make sure that the EGR valve opens when vacuum is applied to it, it could be stuck in the closed position.

Your new manifold setup shouldn't be the cause of this fortunately. All the ECU looks for is valve lift, it has no way to measure EGR flow, etc.
 

· Life Ruiner
Joined
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4,868 Posts
Discussion Starter · #3 ·
Kenso said:
There are 2 control solenoids that operate the EGR valve, one is vacuum operated, the other is electrical and is controlled by the ECU. Either of those may have failed. You can bypass the green/white vacuum controlled valve pretty easily. Quick way of narrowing it down. Cheap "fix" but whatever works. Basically you want the electric solenoid to supply vacuum directly to the EGR valve rather than through the vacuum solenoid. If this corrects the CEL, you've isolated the faulty component. You can check the electric solenoid by applying power/gnd to it and confirm that it is opening properly. Also make sure that the EGR valve opens when vacuum is applied to it, it could be stuck in the closed position.

Your new manifold setup shouldn't be the cause of this fortunately. All the ECU looks for is valve lift, it has no way to measure EGR flow, etc.
So you want me to run the hose the goes into the vacuum control valve to the EGR valve?
 

· Life Ruiner
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4,868 Posts
Discussion Starter · #5 ·
ok, the control solenoid already routes to the EGR Valve via the upper of the two nipples on the bottom of the solenoid.

so what i did is routed the intake manifold vacuum away from the CVC and directly to the control solenoid bottom nipple, right?


Basically #5 goes directly into the control solenoid upper and #11 leaves the control solenoid bottom and connect to the EGR valve. CVC totally bypassed.

Is this right?
 

· Life Ruiner
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4,868 Posts
Discussion Starter · #7 ·
For those searching:

Results were that my EGR sensor the one atop the EGR valve was not sealing to the valve top, thus not creating vaccum. I used RTV to seal it and no more CEL.

Thanks Kenso for helping me understand the system.

~TRu Hybrid
 
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