[2.5x_sleeper]

Take a look at the picture below. It shows the 2008 model where the external ATF filter was deleted. No external ATF filter after the 2007 model year. No external ATF filter on the 2010.

Bobby...

['07 FSXT Member Journal] ['03 X Member Journal]

 

[mhackney]

Remember I have a 2010.

 

[2.5x_sleeper]

@mhackney yes, I realized that & edited my post to direct it to your 2010 mode!

Looking at your profile, you have 2010 in the "Personal Details" & 2005 in the "Profile Info". What you have in your "Profile Info" appears under your avatar! Hence the confusion! Would you like me to change that to 2010 for you?

Bobby...

['07 FSXT Member Journal] ['03 X Member Journal]

 

[mhackney]

Sorry! I’ll fix that now.
<=== done!

 

[mhackney]

I can verify my 2010 has the filter delete so it's on to the next thing to test - whatever that may be.

I got a copy of the Subaru Service Manual late last week and I'm gone through it many times looking for diagnostics and anything that might shed light on this problem - to no avail. I'm sure if I take it to a mechanic it will turn into a money pit without resolving the issue.

 

[551602]

I had something similar happen and was at a loss as to what it was, so took it to my local dealership. Basically, all was good except for the idle running too low, and they reset it with their scan tool and suggested doing an upper intake cleaning with the chemical stuff they suck into the intake through a vacuum tube. The car has 173,000 miles on it and I had never had that done in the 3 years I have owned it, and I am not sure it had ever been done. The good news is it's done wonders to the pedal response and stabilized the idle. No issues coming off the highway anymore.
I suspect that my intake was gummed up enough to disturb airflow, and made the idle relearn difficult. That or it's trying to do the procedure in very hot weather that simply doesn't work. I know that Nissan requires the ambient temp to be in the 20+C range or roughly 70 F, and trying to do an idle relearn in hot temp or temps approaching freezing would always fail. I am guessing but the weather has been hot in most places in NA, and I think it's possible that despite your attempts the idle relearn is not taking. If you can either have a dealer reset it or try doing the idle relearn when the temp is around 70 F.
Good luck.

 

[mhackney]

Thanks for this. Do you recall if your idle speed was not affected of the car was in Park or Neutral but dropped simply putting into drive?

On the relearn procedure - it is interesting that I can't find anything about that in the official Subaru Service Manual. You would think that it would be documented if required.

I do plan to clean the throttle body thoroughly. I haven't looked at it yet. Cleaning the intake should be straight forward too.

 

[551602]

From past experience, if the idle relearn hasn't worked the car's idle drops when put in drive to the point of wanting to stall out and does the same thing at stop signs. Or it can just be running at lower than usual rpm.
Part of why I chimed in was that the most recent event that led me to the dealership involved getting a code P0302 but the coil and plug were fine when I checked. After clearing the code I later took it onto the highway where it was driving great, but when I left it the Foz died making a right turn onto the roadway. No malfunction light, or pending code when I checked later, but the car would not start. I killed the battery trying. Had to be towed home. Made appt at dealer for next Monday, and put the battery charger to work. The next morning, it started up fine with no issues other than the low idle. I drove it to the dealer finally for the appt, and the tech took it out for a couple of test drives and couldn't really find anything wrong other than to comment on the idle and ask if the battery had been disconnected. He reset and said it was fine and that the car might benefit from the intake cleaner. He was right. I am hoping yours is as simple. Cost me $300 all told for the service and diagnostic.

 

[mhackney]

Thanks, this really does sound related to my problem. I can also say that it was very hot when I did my resets - 95F to 99F. It is cool this week so I might attempt it again. I should also say that the description of the reset with the idle increasing and decreasing during the relearning did not happen any of the times I attempted it, it pretty much went to the idle speed and stayed there the entire time. In several cases the battery was disconnected overnight so I am sure it should have reset.

 

[551602]

. It's like idle learning can be finicky. I had disconnected the battery to remove the no2 plug and then did an idle relearn in maybe 85 F weather. Started and idled fine for the first period, then when I went to start the second bit it died and I had to restart it and give it a bit of gas. Let it run the 12 minutes or whatever and then just took it out for a test ride. Idle was a bit low but it wasn't dying at stops and seemed fine during city and parkway driving.
I probably should have repeated the procedure again later but I didn't. It conked out in 90 F weather coming off a 40-minute highway run.
Fingers crossed good luck with trying it again under cooler conditions

 

[aleekat]

Once you posted it's fine in P & N, I suspected transmission issue. In the old days that would be a kick down cable issue, but no clue on Subaru,

 

[nvuono]

@aleekat,

I’d suspect the same since when my 2010 FXT had low transmission fluid (leak from radiator connection) it would stall at a stop but otherwise drive fine. I remember checking AT fluid level wasn’t completely obvious

 

[mhackney]

An update.... When I disconnected the PCV to get yesterday I had not driven it again until tonight. It was 70F out and the CEL was lit so I pulled out my iPhone app to clear it. This apparently clears the idea settings too (?) as the app said it might run rough while it relearned - which it did. And then after, it ran fine and no matter how hard I tried I could not get a stall coming to a stop. Idle dropped but no flickering dash lights or stall.

Don't know if this was a relearn thing or because it is much cooler tonight thing,

But, I am picking up the Subaru Engine Cleaning kit tomorrow and I found what is probably the last Subaru top end cleaning tool. This is used to control the sucking of the intake cleaner into the intake. I'll remove and clean the throttle over the next day and hopefully the tool will arrive on Saturday.

 

[Bdkdave]

@mhackney,
The only factors here that changed after you did the work was disconnected the battery and cleaned the mass airflow sensor. All that other stuff including the EGR was not effected because it wasn’t an original problem ( although it is good that you attended to it). First off. In the future do not disconnect the battery unless you are doing some electrical work or something that specifically requires the battery removed. ( always disconnect the negative first and install the negative terminal last. Less sparks. Less chance you will spike a driver in the ECM. Which is a possibility- just unlikely. Do I wouldn’t worry about that just yet. Changing plugs, coils,oil, etc. no need to disconnect the battery if you are careful and of course the ignition is off. You eliminate the possibility of this being a cause of your new symptom. It is not unsafe to do engine work with the battery disconnected. Or at least buy one of those 9v battery adapters that plug into the 12 volt power plug in the console to keep the computer memory powered.
Second, replace you mass air sensor! You touched it! No matter how carefully, stalling is a major symptom of. Faulty MAF in any car! Everything else was not a problem before you started work on it. Other poop wasn’t going to just break because of the earths rotation! It is logical at this point. What you messed with would cause new symptoms. Not what you didn’t mess with!! MAF’s are notoriously sensitive and cleaning, even with the MAF specific cleaner along with removal can and does cause failure occasionally.
CHANGE IT!!! Do not try and diagnose it with an ohm meter or check for a 5 volt reference to make yourself feel better. Do not even check for a signal wire! I have scoped these sensors hundreds of times with a ten thousand dollar high sampling rate oscilloscope with hundred of hours of professional training as a student and instructor. It is useless! They almost always read fine! No faults. Very infrequently will this problem set a trouble code. The only good a scope does is if you can monitor it with another person driving and you will see the signal drop out just before the car stalls verifying the sensor is at fault.
Even if I am wrong. With that mileage the car would benefit fro a new one anyway! Because you touched it the only reliable way to remove it from the equation is to replace it! Use a subaru part for this! Even new aftermarket MAF sensors have a 50% defect rate out of the box! Never use a remanufactured one!! Total wast of time!!! Don’t touch the sensor end! Ever!!

 

[551602]

FYI in my case, I had replaced the MAF before my misfire incident and then later stall incident. I had replaced it because a week prior I got a running rich code that pointed to the MAF. Swapping it out for a Denso one I got at a pick-and-pull yard 9 months ago fixed that issue. In my opinion, successfully resetting the idle is even more crucial when you have replaced the MAF.
I can say I tried to replace mine with an NTK sold through their WVE line over a year ago and that proved to be defective and was causing transmission shift issues. I contacted them and their engineer said that the MAF is not a part to replace unless defective, and suggested reinstalling my old one. I did and the issues related to the new one went away. So I would not be so quick to suggest it needs replacing in this case when the codes registered don't point that way.
Cleaning it is a good and easy bit of maintenance as long as you use proper MAF cleaner, and realize that the sensor measuring air flow is the one deep down the tube on the inside rather than the easily visible temp sensor part towards the outer tip.
The proof will be in the pudding. I am optimistic that an intake cleaning and proper idle relearn in more moderate temperatures will allow the ECU to regulate air and fuel better, and get idle in the proper range.

 

[mhackney]

You both make good points - especially Bdkdave's point that "Everything else was not a problem before you started work on it." I've thought that several times.

As for my MAF - I cleaned it with brake cleaner, not the proper cleaner. I think I'll pick up a new Subaru MAF when I pick up the engine cleaning kit at the dealer today.

My plan is:

1) replace the MAF with Subaru part and test drive (do I need to do an idle relearn here?)
2) clean the throttle - test drive
3) top engine engine cleaner - test drive
4) Subaru fuel injector cleaner - test drive

 

[551602]

The idea that everything was working fine prior is mistaken. Things have to be quite bad for a code to be registered. I think you should do all the maintenance above, then do an idle relearn followed by a test drive.
There is a possibility you damaged the MAF by cleaning it with brake cleaner.
FYI I have noticed that at Pick and pull yards it is not unusual to see a new or newer MAF on vehicles. It's how I grabbed the one I am using now. I suspect it's one of those relatively inexpensive parts that people try before giving up on the vehicle. For once in my life, I showed a bit of foresight by picking one up for $12. Otherwise if going aftermarket I am pretty sure that Denso is the OE supplier for Subaru SH generation MAF sensors and was used widely across models from 2009 to 2016

 

[rocforstr]

One more possibility, based on my experience with a 2014 Escape (don't laugh - replaced it with a 2020 Forester!). It had an issue with the AC pulley clutch not disengaging when the AC was turned off. Once the weather cooled down in the fall that year, and I stopped using the AC constantly, the problem cropped up.
The system was designed to boost the idle speed when the AC was on, but that did not account for the clutch staying engaged when the AC was otherwise "off". So of course this caused stalls when stopping/idling under load. Ford dealer replaced the clutch after agreeing with my diagnosis, and all was good after that.

Maybe there is something similar at work in this situation?

 

[mhackney]

I just got back from my local Subaru parts dept. Man are they friendly. Got the cleaning kit and the MAF sensor - ouch but they were a bit cheaper than many online genuine parts places. I am thinking I might replace the MAF after I do the cleaning stuff "just in case".

 

[551602]

Good luck. I still maintain the idle relearn will be key. I kind of wish we had a Subaru tech or master mechanic here as we did in the Nissan Forum. There it was explained to me that it had to be done at a certain ambient temperature range, which explained why I could not do it manually outdoors in almost freezing weather. I am sure the same would apply if it was too hot. I suspect it's the same thing with the Subaru idle relearn, but other than the actual procedure I have not been able to find out much about it.
I do want to buy one of those memory saver units to avoid idle memory loss in the future.