EGR valve

[mikes403regal]

I blew up my EJ25 in my 99 Outback about a month ago. So I bought one from Japan with low miles on it. As most of you probably know they dont have emissions. So no EGR valve. The problem is now my CHECK ENGINE light is on because of the "EGR flow". Does anyone know how to bypass that sensor. Is there a way to put a resistor on it so it thinks everything is working? Thanks for any help.

[Danbob99]

The computer reads "EGR Flow" failures by sensing engine rpm change when the valve is opened. If the EGR valve is not present, it is obviously not going to work to change the engine rpm.

 

I'm not sure of a way to bypass this. Perhaps an ecu reflash.

 

Dan

[lmdew]

Did you check the back of the drivers side head? The port may be plugged in which case you can pull the plug out and put the ERG on.

[987687]

If you were electrically inclined you could design a device to simulate an EGR to the computer. My fear would be that it would run slightly rich because the computer would "think" it was getting exhaust back in the intake when it really isn't.

[Danbob99]

If you were electrically inclined you could design a device to simulate an EGR to the computer. My fear would be that it would run slightly rich because the computer would "think" it was getting exhaust back in the intake when it really isn't.

 

The issue here is that the computer doesn't use a specific sensor to determine the EGR operation. It uses rpm fluctation and manifold pressure. You can trick the solenoid easily, but it doesn't sound like that is an issue in this case.

 

Dan

[987687]

The issue here is that the computer doesn't use a specific sensor to determine the EGR operation. It uses rpm fluctation and manifold pressure. You can trick the solenoid easily, but it doesn't sound like that is an issue in this case.

 

Dan

 

So there isn't a signal that says "Open the EGR now"?

[Danbob99]

There is a signal that says "open EGR now" and that comes from the ECU and goes to the EGR Solenoid. The EGR solenoid opens and passes vacuum pressure to the EGR valve. The computer knows wheather the solenoid is open or closed; and would give a code for EGR Solenoid operation if there were an issue with that. The P0400 code for EGR Flow is triggered when the computer commands the EGR Solenoid open and the engine RPM and manifold pressure do not change, indicating that the EGR valve is not operational.

 

Dan

[idosubaru]

someone else has a thread (posted to today) about this same issue.

 

you can ground an ECU pin to make it think it's a manual trans, which also didn't have EGR and the EGR code will go away...or at least one of them. problem is there are multiple codes associated with removing the EGR and the other codes are still present.

 

in short it's not easy, but i realize being from Maryland you can't have the check engine light on. i have the same issue on my swapped legacy but since I moved to WV (from Westminster, MD down the road from you actually) I don't have to worry about the check engine light so I ignore it.

 

You do have one option that would be guaranteed to work and that is to install the original intake manifold with EGR (or get another manifold that has it) and install it. Then plumb the EGR valve into the exhaust. Haven't seen anyone do it, but it would work but would require some custom piping from the original EGR location in the head to the actual exhaust header itself.