Check Engine Light

Sorry to keep bugging you guys, but this is my first "late model" Subie and I have lot's of questions.

After having my new/used '97 Outback checked out by my mechanic the Check Engine Light came on. While I hung around they did some work on the car and cancelled the light and it was fine till I got home and the light came back on (5 miles). I went back and they futzed around with the car again, were pretty sure they found the problem (they accidentally pulled a vacuum line), and the car was fine for three days until today when the light came back on.

They told me whatever it is not to lose sleep over it because it's not serious, so I'm still driving it. Anyway, the light went out for awhile and then came back on again for no reason. Not sure what will happen tomorrow.

I've read that the Check Engine Light itself can be problematic, and will come on when nothing is wrong, and may take up to 10 start cycles to get it to reset.

I plan to take the car back to my mechanic (the light was fine when I test drove the car, picked up the car and drove it back home which amounted to about 75 miles). Anyway, as I said, I plan on taking the car back to the shop (they have all the computers and stuff), but does anybody have any thoughts on this problem? I know the previous owner, and he mentioned a lot of things, but never mentioned any problems with the Check Engine Light, except when he accidentally started the car without putting the gas cap on.

tia

Sheldon

Reply to
Sheldon
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When that light comes on it means a trouble code has been stored. In order to properly diagnose and repair the cause, that code must be read and the appropriate troubleshooting procedure followed to narrow down the problem. Just clearing the code to turn off the light is not a true repair, as long as the condition still exists the code and light will come back. Your mechanic should be able to read the code and fix what is wrong, he should not be clearing it and sending you on your way.

Reply to
mulder

Your understanding is not far off the mark; the "check engine" light is a warning that something is wrong that you might not otherwise notice and that something points to the emissions control one way or another. (Some cars add extraneous stuff to the light, but I don't know of any that mean you have to stop driving as long as it responds okay.) It doesn't really come on "when nothing is wrong" but the "something" can seem pretty trivial.

You should have the mechanic see what code is bringing in the light now, since it is always possible this is something new that popped up in the last few days. If the problem before was a vacuum line, it is also possible that the system is complaining about "fuel trim" - that it was getting used to the way it was handling the mixture when the hose was off, and now has to readjust to the way it should have been. If that's what it is, one more code clear at this point should do the job.

Mike

Reply to
Michael Pardee

If it were me, I'd take the car to a different suby dealership.

rj

Reply to
rj

I have a 99 Imprezza and had the same symptoms in that the check engine lite would go off them come on in a couple days and the cycle would repeat. Fixed it by simply replacing the air filter (which was definitely due to be replaced). Hopefully, your dealing with something that is not going to be a major repair, also.

Tony

Reply to
Tony

At the very least, you need a mechanic that can fetch the trouble code and tell you what it means. If he/she can only read the code, somebody here can tell you what it means.

Run, don't walk from that mechanic.

Reply to
Jim Stewart

No, they have all the equipment and read the code. We thought it was fixed.

Reply to
Sheldon

Am currently having a similar problem with the CEL on my 05 OB 2.5i and this might interest those of you with the same model.

Last week I took it to a Subaru service shop where they said it was an unusual code, reset something to clear it, but still said it might come back.

Sure enough, on the way home about 200k later the light came on again.

The service mgr. had told me the code was:

" P2097 (POST CATALYST FUEL TRIM SYSTEM TOO RICH BANK 1)"

So I did some Googling for P2097 and found the following - anyone know anything about it or what it means?

******************************************** Quote: Originally Posted by mwiener2 And now they're looking into finding that TSB. They called the SOA tech line, but the tech line hasn't called them back yet.

There is no TSB as of yet, but the Tech Line is aware of the issue and the reflash.

Here's a little more info I drummed up on ECM (Electronic Control Module)Reflashes:

Quote: Logic Change #1 (U6) Federal Emission Specification Only - 05MY Legacy 2.5L M/T & 05MY Outback 2.5L M/T

Conditions: 1) - P1160 (RETURN SPRING FAILURE), 2) - P2097 (POST CATALYST FUEL TRIM SYSTEM TOO RICH BANK 1), 3) - Cruise Control Intermittently Shuts Off, 4) Surging during moderate acceleration.

Affected ECM's CID (Calibration Identification Number): E2ZJ133B

Quote: Logic Change #1 (U5) California Emission Specification Only - 05MY Legacy 2.5L M/T &

05MY Outback 2.5L M/T

Conditions: 1) - P1160 (RETURN SPRING FAILURE), 2) - Cruise Control Intermittently Shuts Off, 3) Surging during moderate acceleration.

Affected ECM's CID (Calibration Identification Number): E2ZJ133A

Quote: Logic Change #1 (U6) Federal Emission Specification Only - 05MY Legacy 2.5L 4EAT &

05MY Outback 2.5L 4EAT

Conditions: 1) - P1160 (RETURN SPRING FAILURE), 2) - P2097 (POST CATALYST FUEL TRIM SYSTEM TOO RICH BANK 1), 3) - Cruise Control Intermittently Shuts Off, 4) Surging during moderate acceleration.

Affected ECM's CID (Calibration Identification Number):

05MY Legacy 2.5L 4EAT - E2ZJ131B 05MY Outback 2.5L 4EAT - E2ZJ132B ******************************************************
Reply to
eachcornerpulling

Essentially, the problem appears to be related to a quirk in the ECM (ECU). The secondary O2 sensor is supposed to be to monitor the effectiveness of the catalyst, setting a "catalyst efficiency" code if the sensor reports spikes of CO coming through. The code seems to be saying it's not spikes it's seeing, but an elevated level of CO coming through.

However, such things can actually happen if the ECU can't properly control the mixture. For example, a dripping injector can feed uncontrolled blurps of fuel that the ECU can only control by reaction. Once the effect of the drip passes the front O2 sensor the ECU quickly readjusts to the current conditions while the catalyst still hasn't received the oxygen needed to process the drip.

I suggest a bottle of injector cleaner is a cheap way to "wave the dead chicken." Can't hurt, might help. Also the OP can keep an eye on the oil consumption, since that is a potential sidestream source of HCs, which translate into CO. In the alt.autos.volvo group there have been reports of older Volvos failing HC emissions but later passing when the oil was changed. That sounds weird to me but even the top guru has recommended changing oil after failing HC tests, so maybe.... And maybe a run of several miles on the highway will help if the vehicle hasn't had one lately. As far as a solid fix goes, I'm at a loss.

Mike

Reply to
Michael Pardee

On Sun, 26 Feb 2006 14:10:12 -0700, "Michael Pardee"

Thanks, Mike, and I'll try a bit of injector cleaner. As you say, It can't do any harm.

As for a good run on the highway, just been there, done that. The most annoying thing is that the cruise control is flashing and automatically disabled when the CEL is on.

But referring to that info I dredged from another forum, was I wrong in thinking it indicated the ECM firmware could be "reflashed" to solve the problem?

Another Mike

Reply to
eachcornerpulling

Light was on this morning, and went out by itself this afternoon. This is frustrating.

Reply to
Sheldon

This was happening to my daughter's '01 Forrester last week. I convinced her she needed to take it to the dealer to get it checked and it turned out to be the O2 sensor, which they replaced at no charge under her extended warranty.

Jon

Reply to
Zeppo

We have a CEL issue nobody seems able to resolve. Anyone else had this? The OBDII code is 1507 (idle air motor (failsafe)) - seems consistent with the engine not running properly when slowed down to idle from high revs. It won't run properly again til we turn the ignition off and re-start. We replaced the idle air motor, the O2 sensors, the gas cap, and the computer. Two Subaru dealers tried to fix it. My local mechanic friend joins me in anger at the fact that this cannot be resolved through Subaru resources, and has spent many hours on it trying to analyze it (at no charge, bless him). If anyone can shine any light on this, I'd be incredibly grateful.

Philip Guest

Michael Pardee wrote:

Reply to
casper

They're talking about reflashing the ECU--there's a problem with the original engine operating program and/or parameters, and it sounds like Subaru recognized it and is reflashing to correct it. I'd print out that info and ask the service manager for the reflash.

Reply to
CompUser

Philip,

Don't know whether this will help or not, but it can't hurt. Has anyone tried cleaning the throttle body with carburetor/fuel system cleaner? On some fuel inject cars (and I don't know whether this is an issue for Subaru) deposits build up around the throttle plate and either keep it from closing all the way or sticking. This could confuse the computer and idle air motor.

Ed Plummer

Reply to
Ed P

That I dunno. Most late model cars can accept flash upgrades, but it was a lot less common five years ago even. Maybe somebody knows about your '97.

Mike

Reply to
Michael Pardee

On Mon, 27 Feb 2006 15:38:09 -0700, "Michael Pardee"

Mine is not a '97, it's an 05 Outback 2.5i, so I assume reflashing will be an option. I will post further developments.

Another Mike

Reply to
eachcornerpulling

Curiously, if the WRONG type of solvent is used for this job, there is some type of sealant that can be destroyed in the TB. You might search for this issue over at

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.

Carl

Reply to
Carl 1 Lucky Texan

Sorry about that - I got confused. First time this hour that happened!

Mike (the other one)

Reply to
Michael Pardee

"Zeppo @hotmail.com>"

I took it in today. It keeps coming up as the throttle position sensor. Hope that does it. They'll have the part tomorrow. Also, they did clean out the throttle body.

Reply to
Sheldon

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