[Bravo12]

I'm biting the bullet and taking mine to Cherry Hill Subaru today or tomorrow; I don't think it will make it back up to AZP again. I'll mention the EGR to them, so they can start there instead of spending all my money tracking down a gremlin.

If it's the EGR, this might be something noteworthy to have replaced at 120k, since it seems to be a common issue on 2.5L N/A's with 120k-140k miles. Maybe the EGR is only good for that many miles, and it's only now that the cars are getting there that this problem is surfacing.

 

[Bravo12]

My Foz is at Subaru of Cherry Hill. I'm currently driving a 2011 Legacy! They really stick it to ya with the rental, trying to entice you into buying something new. Luckily, the new Legacy is not really my style. Had they rented me a new Forester with all the interior options, I might have been calling my credit union tomorrow about a new loan. If the N/A motor in the Forester is as peppy as the one in this Legacy, I think I'd be alright with skipping the turbo. Although, the Leggy has a 6-speed auto, and the Forester has a 4-speed, if I'm not mistaken. I'd have to do some test-driving before I'd buy, but at least this Leggy isn't pushing me towards the dark side. I need to buy a house in the next year or so; I shouldn't get into another car loan until after that.

Anyway, I'll keep everyone posted on what they find out after diagnostics tomorrow. Hopefully it's something simple like the EGR or a fuel injector. Got one of our 48hrs of Tristate participants working on it in the morning! :Banane29:

 

[Bravo12]

Subaru of Cherry Hill just called. The prognosis: cracked spark plug in #3 cylinder. Bosch Platinums FTL! I had swapped out the Bosch for an NGK on Sunday in the #1 cylinder, but I didn't do the other three because the scanner was showing misfire on #1. They installed the other 3 NGKs I had in the back of the car, and they say it's running great now. I pick it up at 5.

 

[MN2001ForesterS]

I'm still wondering where my tear-down should begin.

I don't know when the last tune-up was performed, so should I do plugs and wires first?
It randomly turns on a CEL for a rear O2 sensor and then the CEL will go out after a while. Do I replace the rear sensor next?

Or...Do I just jump right on the EGR with a mechanic and hope that it is the issue?

Help?

 

[MN2001ForesterS]

So...
Just got back from a $600 job for plugs, wires and rear O2. Codes for all 4 cylinders misfire tripped when I scanned. Also with a stored rear O2 code.
The car no longer has the significant stuttering issue. Yay!
BUT (and this is a BIG BUT), the strange power loss/surge is happening. It just seems to lose power when it is warm. The weird idle bobbing still happens too. Car now idles higher for a bit when I come off of the gears to a stop (manual trans) and then slowly lowers.

Idle Control Valve?
Mass Airflow Sensor?

Should I reset the ECU (via the battery disconnect method) and see if it helps?

HELP!

 

[forester25xs]

Now firmly convinced this WAS my problem ..... 2 more days of great running. Better than it has in a while. And I had the time to take apart the old EGR. Now certain it MAY be repairable for this type of problem. Pictures explain it below:

1st picture the valve with the 4 screws removed

2nd picture, the bottom of the stepper motor. It moves downward to PUSH the valve open. Then moves upward to ALLOW the spring to return and close the valve.

3rd picture, look into the bottom hole and you can see the plunger. This means the valve is open. The spring is not enough to overcome the shaft binding and close the valve. When the valve it closed, the plunger is seated and you can not see it in the lower hole.

4th picture, from the top, the spring compressed and valve open. Shown in the failing state.

5th picture, the spring as it should be, extended and the valve closed.

Last picture, instead of making the aluminum blocking plate I described above, you can unscrew the top of the valve, while on the engine. Make certain the valve spring is ALL THE WAY UP, and the motor on the top off to the side. This will still set a P0400 code, but give you another way to see if a sticky EGR is the cause of your bad idle.

By the way, I cleaned the shaft inside the upper hole, and used high temp silicon grease on the top shaft, under the spring, and in the upper hole, working it back and forth and have a working SPARE EGR,

So i saw your reply on my "recurring engine failure" post about the EGR. So i went ahead and took it out, took it apart, like you said, and the spring is up, as it should be, doesnt appear to be sticking at all. Here are some pics. WD40 saved the day with those four screws.

 

[forester25xs]

I will update this thread as my diagnoses progresses.

After fixing many a Subaru for idle problems ... now I have had a phantom and not everyday one for a month or so. At first I thought I had bad gas. Car always starts, but from a cold start, after a few miles, if I stop, idle was very rough, I sometimes had to step on the gas to keep the engine running and the exhaust smelled REAL BAD. If I let the car set a few days, it seems to take a longer warmup time before I have a normal idle.

With an OBD reader/monitor I would only see the O2 sensor go nuts ..... that's why I started there. Was it the Cause or Result? Turns out it was the result. Also I had PENDING misfires on all 4 cylinders. P0301, P0302, P0303 and P0304. Never went over the criteria for a misfire, but always pending.

I tried a new front O2 sensor, Engine temp sensor, swapped AIS, TPS, Air Temp Sensor, Map... All no help. Neutral switch was BAD ... always open telling ECU I was never in gear. Again no help there.

Over this weekend, I though about it. I had removed the EGR and cleaned it when I did my engine rebuild last year. ( http://www.subaruforester.org/vbulletin/f88/every-2-5l-interference-engine-64410/ ). Being an ELECTRONIC EGR with a stepper motor, there is no way to see or test if it is open or closed. And at almost $200, I wanted to be certain. So I took an aluminum can, cut it and laid the EGR gasket on top of it. Then I cut the outline and used a hole punch to ONLY punch the bolt holes. Put it in and started driving.

Since Sunday, my bad idle has not returned. I DO get an expected CEL P0400. Happens during the EGR test. About 5 mins into a start, while decelerating ( fuel cutoff time ) the ECU opens the EGR and expects a DROP in the MAP value. With my aluminum plate in place, this obviously does not happen.

So later today or tomorrow, I will bite the bullet and order an EGR. After further searching the internet, Mitsubishi's use a similar valve and their boards are full of bad idle problems caused by it. The Mitsubishi versions however is more than $400 .....

Something to think about if you have any Subaru with this type EGR and an intermittent bad idle problem.

Item #11 in the following Illustration:
http://opposedforces.com/parts/fore...11/type_3/intake_and_supply_system_turbocharger/intake_manifold/illustration_1/

Pictures attached ... 1st is the EGR on the engine
2nd is the valve, gasket and cutout blockout aluminum from a can
3rd is the valve with the gasket then the blockout and bolts in place ready to be put back on..... and smooth my idle ......but give me the P0400 code.

:
Well, everything was going great until i go to put the egr back in and pulling out of my garage i get p1494 and p1496

 

[ferret]

1494 / 1496 sounds like the egr connector is not fully seated

 

[forester25xs]

i actually went back and tightened the two bolts and four screws with all my might and the codes went away!! horrible news though, i think one of my bolts are stripped, it was nearly impossible to screw it back in but eventually i got it and im afraid to take it back out (it being the egr). being that im probably screwed if i cant get that bolt back in if i were ever to remove it agian, im going to leave it alone for awhile.

 

[brnz]

Just wanted to say thanks Ferret. Cleaning/unsticking the EGR valve solved my rough idle / p0400 AND saved me some serious coin.