CEL, cruise, traction rough idle cold weather

Hi,

My bone stock 23k mile '08 LGT 5EAT, recently started to idle rough in very cold weather after partial warm-up. Today it got worse, almost stalling after going from dead cold in 10 DEG F weather to normal temp after 5 min on the highway. After that my dash litup like a Christmas tree, traction light, SEL, flashing cruise light. Tonight it's seems to be running quite a bit better, but the lights including the SEL are still there.

I searched many threads and most are older, anyone have any recent experiences with this on the newer cars?

Thanks,

Paul

I noticed the same thing here. I just got the car not to long ago and the previous owner thought it was an o2 sensor. He had the sensor replaced, and the CEL was cleared. Well, its back, and my abs and cruise light are on as well...

I wish I could get the CEL checked at autozone, but there is a 7 foot snowbank behind the car (parked for winter).

I haven't noticed it idling weird, but when I free rev it a little it feels rough, like its running rich.

You guy's need to have the code read and cleared.

I have been told that Subaru adds more fuel for the first 20 seconds after start up. Tuners can fix that. When you start the car and feel this happen, just rev it for a few seconds and it should clear up.

I poured a can of seafoam in the gas tank about 8 weeks ago and a can of STP injector cleaner from Walmart 2 weeks ago and had the Tuner make some adjustments. Mine seems fine the past few weeks.

Yes, most auto parts places will check and clear the codes for free.

All my Legacy's would throw a CEL light when I got them stuck. Starting the car 4 times normally clears that, you don't have to go to the auto parts store. If starting the car 4 times doesn't clear it, then go see the man...

My '08 Spec.B is currently at the dealership for the 2nd time in a week with the same symptoms. On the first visit a faulty O2 sensor was blamed and replaced, but the problem returned within a few days. On the second visit, the service person said they have had a couple of other customers with the same problem and it turned out to be deteriorated intake manifold gaskets, allowing extra air to be drawn into the intake and making the air-fuel mixture too lean. They have kept my car overnight to run tests and submit the data to HQ for analysis before they do the warranty work. There seems to be a problem related to these gaskets in some GT / SpecB's (07-08?). There are other posts on this forum related to this problem and mentioning the following codes (these codes are from the forum, not from my car):

P0171 mixture too lean

P0301, P0302, P0303, P0304 cylinder random misfire

Love my car. This is my first issue to date, hopefully it will be resolved soon.

how many miles on your spec B? mines starting to idle low every now and then... nothing that throws codes though (Yet). i'm at 41k (roughly)

Sorry to thread jack OP.

my traction control light comes on when i get wheel slip from ice or snow... doesn't stay on though...

'Mileage' is 32,500 kilometres, approximately. The lumpy idle has been developing for a while, culminating in the CEL recently. It would idle a little high sometimes, and at other times a little low. I originally thought that the occasional 'rough' feeling was due to low rpms, but upon reflection, I think it actually was when the cylinder misfires were occurring (usually at low rpm), because at other times the low idle speed is silky smooth. I feel that it may be exacerbated by cold outdoor temperatures, but I'm not certain of that.

I've also not yet received confirmation from the dealership that this is indeed the problem, I'm waiting to hear from them.

this happened to me twice. One time i got stuck pulling out of my driveway in the snow and another i got stuck in the snow. It had the ABS on for a minute then CEL and blinking cruise. I took it to pep boys get it flashed for free and the guy said that its a sensor that get triggered when your wheels are slipping bad or something like that. He said nothing to worrie about. This happened to me twice and nothing seems to be going wrong since then (knock on wood). The code was ??55, i beleive it was 2 letters before 55. If anything pep boys idk about autozone will flash it for free.

This sounds about right. The lights came on when I almost got stuck in a snow bank. It took a little while spinning all four but I got out:cool:. I will go pull the negative terminal on the battery and will post back if the code comes back...

I have my car back, complete with new intake manifold gaskets. On the drive home it behaved well, idling smoothly a little below 1000 rpm when stopped. We'll see how it is on a cold start in the morning...

Please let me know if this solved the problem... Also, any way you could figure out how many hours of labor it took them to replace the Intake Manifold gaskets? I wonder if its easy enough to do "yourself".

New owner of an '05 GT, my first Subaru and loving it. Got hung up last night trying to get into a parking space in Cambridge MA. The plowing here is pretty poor (read pathetic) and they leave slush/frozen piles to navigate through. After a few tries rocking it I was free but my dash lit up with the CEL, ABS and blinking Cruise. Drove about 10 miles to and from work today and while the ABS has gone off the other two remain on. The roads were terrible today and I enjoyed the pushing the all wheel drive though probably not the best idea with a dash full of warning lights.

After reading the prior posts its seems the car will be fine to make the trip to the mountains this weekend?? I am hoping so, she is not leaking any fluids and the temp holds true. Should I take it in to have the codes read?

Please let me know if this solved the problem... Also, any way you could figure out how many hours of labor it took them to replace the Intake Manifold gaskets? I wonder if its easy enough to do "yourself".

I'll post again once I've had the car on the road in a variety of conditions; the problem was variable and intermittent, so although I am optimistic that it is fixed, time will tell. The labour was 2.3 hours according to the work order. The parts were inexpensive. I'm sure others here can comment on the DIY factor, but I don't know how difficult it would be. Also note that to diagnose the problem they used both engine codes and some kind of cold-start diagnostic test; your problem could be similar, or it could always be something else altogether.

New owner of an '05 GT, my first Subaru and loving it. Got hung up last night trying to get into a parking space in Cambridge MA. The plowing here is pretty poor (read pathetic) and they leave slush/frozen piles to navigate through. After a few tries rocking it I was free but my dash lit up with the CEL, ABS and blinking Cruise. Drove about 10 miles to and from work today and while the ABS has gone off the other two remain on. The roads were terrible today and I enjoyed the pushing the all wheel drive though probably not the best idea with a dash full of warning lights.

 

After reading the prior posts its seems the car will be fine to make the trip to the mountains this weekend?? I am hoping so, she is not leaking any fluids and the temp holds true. Should I take it in to have the codes read?

I wouldn't worry about getting the codes read yet. It sounds like you just need to pull the negative terminal on the battery.

Like mentioned above, the code was probably tripped when you were trying to get unstuck. If the code comes back after you reset the battery I would take it somewhere to be read (somewhere they read them free, of course).

Thanks for the feedback. I'll be curious to hear SpecD how your car does now that they've changed the gaskets.

I kept mine in my garage for a couple of nights, I also checked vac lines and opened the air box and resealed to be sure it was tight.

So far no more problems, and the codes cleared. I'll try leaving it outside a couple of nights this week to see if the problem returns.

Codes from spinning the wheels are a separate issue Mr.TUL, should be fine after a few restarts.

Paul

Mine did therough idle while sitting in stop and go traffic last night. Checked the code, P0172 rich bank.

I'm thinking it's those gaskets.

I carry my scan reader with me now.

Intake manifold gaskets are probably the culprit. There are a few threads on here about the cold idle issues/CELs (you may find some helpful information in them.) It looks like some dealerships have been good about finding the problem and fixing it, while others (like mine,) say they cant do anything.

Here are some of the threads:

http://legacygt.com/forums/showthread.php/p0171-cold-idle-problems-154213.html

http://legacygt.com/forums/showthread.php/odd-idle-only-cold-misfiring-151161.html

Thanks for the feedback. I'll be curious to hear SpecD how your car does now that they've changed the gaskets.

I kept mine in my garage for a couple of nights, I also checked vac lines and opened the air box and resealed to be sure it was tight.

So far no more problems, and the codes cleared. I'll try leaving it outside a couple of nights this week to see if the problem returns.

Codes from spinning the wheels are a separate issue Mr.TUL, should be fine after a few restarts.

 

Paul

So far so good. Idle is smooth.

Intake manifold gaskets are probably the culprit. There are a few threads on here about the cold idle issues/CELs (you may find some helpful information in them.) It looks like some dealerships have been good about finding the problem and fixing it, while others (like mine,) say they cant do anything.

 

Here are some of the threads:

http://legacygt.com/forums/showthread.php/p0171-cold-idle-problems-154213.html

http://legacygt.com/forums/showthread.php/odd-idle-only-cold-misfiring-151161.html

Thanks, that's kind of what I'm leaning towards. This time the light came on after sitting in stop/go traffic, move forward 30 feet and stop, move forward 25feet and stop a few times.

This was after a 20 minute drive from the body shop, a stop at the crowded gas station. Figure out I'm at the wrong gas pump, start the car, turn it around, stall it once in the snow, get gas, rump on it leaving the gas station, drive about 2 miles and sit in traffic. The CEL came on after about 5-7 minutes in stop/go traffic.

Went to my sons house got the code reader, cleared both P0172's and the car was fine for the drive to VT. Did a few 70-110mph burst on the way up after sitting in traffic again in Springfield MA on RT91.

So my engine was well warmed up when this happened.

OH well, I'm going to try and make it till late April when the plan is to rebuild the engine.

My '08 Spec.B is currently at the dealership for the 2nd time in a week with the same symptoms. On the first visit a faulty O2 sensor was blamed and replaced, but the problem returned within a few days. On the second visit, the service person said they have had a couple of other customers with the same problem and it turned out to be deteriorated intake manifold gaskets, allowing extra air to be drawn into the intake and making the air-fuel mixture too lean. They have kept my car overnight to run tests and submit the data to HQ for analysis before they do the warranty work. There seems to be a problem related to these gaskets in some GT / SpecB's (07-08?). There are other posts on this forum related to this problem and mentioning the following codes (these codes are from the forum, not from my car):

 

P0171 mixture too lean

P0301, P0302, P0303, P0304 cylinder random misfire

 

Love my car. This is my first issue to date, hopefully it will be resolved soon.

These are exactly the symptoms and codes our car has (20K mile 08 LGT 5EAT). As soon as we have a 40 degree plus weekend I'm replacing the intake manifold gaskets (the car's out of the bumper-to-bumper and I don't feel like dealing with a dealership). As a point of note it seems like there's a certain range where the car's not quite fully warmed up where the gap opens up enough to lean the car out in vacuum situations (like being stopped at a stop light). With my wife's car if she makes it through a certain area (about 7-9 minutes after starting the car) without stopping she's pretty much guaranteed to not get the CEL, however if the temps are below 20-25 F and she has to stop at a light in this area it seems like there's a 50-50 chance it'll throw the CEL.

**edit: spec.D do you mind tossing up what the part numbers are for the replaced gaskets for the DIY-types like myself? Thanks!**

These are exactly the symptoms and codes our car has (20K mile 08 LGT 5EAT). As soon as we have a 40 degree plus weekend I'm replacing the intake manifold gaskets (the car's out of the bumper-to-bumper and I don't feel like dealing with a dealership). As a point of note it seems like there's a certain range where the car's not quite fully warmed up where the gap opens up enough to lean the car out in vacuum situations (like being stopped at a stop light). With my wife's car if she makes it through a certain area (about 7-9 minutes after starting the car) without stopping she's pretty much guaranteed to not get the CEL, however if the temps are below 20-25 F and she has to stop at a light in this area it seems like there's a 50-50 chance it'll throw the CEL.

 

**edit: spec.D do you mind tossing up what the part numbers are for the replaced gaskets for the DIY-types like myself? Thanks!**

14035AA492 GSKT-INT MANIF (4 UNITS)

14035AA421 GSKT-INT MANIF (2 UNITS)

Note that I am in Canada, so not sure if US part numbers would be the same or not. As for being out of the comprehensive warranty, others on this forum have reported that this was covered for them under the powertrain warranty, which is longer.

I am having the same problem with my 2008 LGT. About 44k miles on the ODO. Rough idle, CEL. Codes indicated that all four cylinders misfired.

Friend with same car and 90k+ miles has same issue.

Here is a detailed DIY walkthrough that I have created... http://legacygt.com/forums/showthread.php/diy-rough-idle-cold-start-cold-temps-lgt-07-09-155325.html

Thanks!

This sounds like Sube needs to issue a recall.