Check Engine Light

[Sheldon]

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

 

[mulder]

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

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.

 

[Michael Pardee]

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

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

 

[rj]

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

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

rj

 

[Tony]

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

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

 

[Jim Stewart]

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.

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.

 

[Sheldon]

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.

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

 

[eachcornerpulling]

On Fri, 24 Feb 2006 21:49:33 -0700, "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
******************************************************

 

[Michael Pardee]

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:

<details snipped>

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

 

[eachcornerpulling]

<details snipped>

Essentially, the problem appears to be related to a quirk in the ECM (ECU).
....
I suggest a bottle of injector cleaner is a cheap way to "wave the dead
chicken." Can't hurt, might help....
...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.

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

 

[Sheldon]

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

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

 

[Zeppo]

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

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

 

[casper]

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

 

[CompUser]

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

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.

 

[Ed P]

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

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

 

[Michael Pardee]

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

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

 

[eachcornerpulling]

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.

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

 

[Carl 1 Lucky Texan]

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

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 www.usmb.net .

Carl

 

[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

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

Mike (the other one)

 

[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

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.