bypass egr valve on ej25 engine

[michel]

I would like to know how i can bypass the egr valve.

i change my usdm ej25 for a jdm.

thank's for help

[idosubaru]

unless you retain EGR you'll get a check engine light that is impossible to work around, so you'll only want to do this if your laws allow a check engine light. many states down here won't pass inspection or emissions like that. i'm fortunate to live in a state that it doesn't matter, so i have my EGR deleted because i did essentially the same thing you're trying to do.

 

i removed the EGR on mine when i swapped engines just because i don't like EGR and it's unnecessary....and it doesn't matter where i live.

 

you don't say what you're doing or what the issue is exactly so i'm going to infer. more details help a lot when all we have is words.

 

i guess the JDM doesn't have EGR? and the JDM wiring harness connectors are different? you have a couple options:

 

bolt your intake manifold on top of the JDM engine. you get your original wiring but you're left with the EGR stuff from the intake manifold but nothing on the engine (i'm guessing since you don't say). that's basically what i did with mine. just make a block off plate to cover the hole on the intake manifold, that's it. some subaru engines that came without EGR have a Subaru block off plate on them - i used one of those.

 

you could also swap your intake manifold wiring harness onto the JDM intake so then you don't have to mess with the block off plate.

 

you could also install your intake manifold and devise your own plumbing of the EGR pipe down to the exhaust manifold, thereby retaining your EGR system. that's probably the best option for most people to just keep everything stock and happy.

 

*** this last option is the only way to not have a check engine light constantly on the car (not counting removing the light bulb for the check engine light ):lol:

 

all of the other methods will result in a check engine light. there is no work around, you can cut wires, install resistors, and even install ECU's from cars without EGR (which i've done) and for some reason no one has been able to figure out a work around. so unless you're really gifted and have time you don't want to attempt this without being totally excited about having the check engine light. it allows you to talk about your engine swap a lot more "hey why is your check engine light on...??"

[michel]

thank you very much for the detailled answer.

I'm living in Québec, and there is no problem to drive with check engine light.

I've already changed the engine, and kept the jdm intake, but i've changed the

electrical harness.

The engine is running, but the idle is very high and irregular (1500rpm to 2500)

Some mecanics told me, that is better to keep my old intake maybe for the difference between injectors.

If there no solution to solve the problem of idle, i envisage to remove the jdm

intake and replace it with my old intake and bypass the egr valve with a plate

as you suggest. Maybe it's the easiest solution?

Thank you again for your help

[idosubaru]

i'm not really sure but i don't think you should have idling issues with the JDM intake.

 

are they both DOHC or both SOHC or did you mix and match Phases? Mixed phases have idling issues. retaining the same phase shouldn't have issues.

 

have you checked the check engine light to see if you have any codes?

 

i would clean out the idle control valve first and see if that smooths things out. your harness swapped on the JDM intake should run and idle just fine.

 

oh yeah - the JDM might have one of the block off plates on it like i mentioned? if so just remove the one bolt holding it in place and install it on your USDM intake if you go that route.

[michel]

both engines are dohc.

There is no plate on jdm intake, but a hole and a plug. I think i will need to built a custom plate or look for one as you described.

I can't check the codes for the check engine, i'm not equipped for it.

What do you mean by phases? I'm french speaking so i sometimes miss some technicals words. Maybe it could help to fix that for my idle issue.

thank again for your help

[idosubaru]

in the US many of the national, larger chain of stores will read check engine lights for free. i've bought scanners for $30 off ebay, well worth it to check and erase the codes yourself.

 

it's a waste to assume or do any work without reading those codes. it might tell you exactly what is causing the issue. no point in replacing the entire intake, harness, dealing with an EGR block off if an idle controller just needs cleaned or replaced.

 

if they are both DOHC then phase is not your issue.

 

to clarify what Phase means, in the US the EJ25 went through some changes in 1999.

 

1996-1998 and some 1999's are Phase I EJ25 and DOHC

 

subaru made some changes around 99 to the idle control, electronics, valve train, etc.

 

some 1999 and all 2000+ EJ25's are Phase II EJ25's and SOHC.