2004 Outback Fuel Mapping and driveability

[R Jacobs]

Last fall I bought a 2004 Manual Outback after test driving the 2003.
Relative to the 2003, the clutch was rougher. More importantly, the
car lurches its passengers forward whenever letting up on the gas -
especially in lower gears, as in stop-and-go traffic. The kids were
getting motion sick! Our interpretation is that the fuel mapping has
changed - and fuel is cut off too quickly when the driver lets up on
the accelerator. Furthermore, the mileage is much poorer than the
literature would suggest. We got 8-9 km/l on the highway, but the
specs suggest 11 km/l. I've not before encountered such a large
discrepancy between promise and reality in mileage.
Our dealer was very sympathetic, and attempted multiple tweaks in the
shop- but ultimately, we drew in customer relations at Subaru Canada.
Although they initially acknowledged there was a "driveability
problem" with the 2004, and they knew there was a "fix in the works",
they left the dealer to their own resources to resolve our problems.
Ultimately we moved to an automatic, paid the difference, and a little
more for "wear and tear". The dealer likely made no money on the deal.
They unloaded the car on a jeep owner who likely spends little time in
stop-and-go traffic. Overall, having the manufacturer leave the table,
after acknowledging a problem has me loose confidence in the product.
Has anyone else had similar observations with fuel mapping or
mileage, specific to the 2004 Outback?

 

[Verbs Under My Gel]

Last fall I bought a 2004 Manual Outback after test driving the 2003.
Relative to the 2003, the clutch was rougher. More importantly, the
car lurches its passengers forward whenever letting up on the gas -
especially in lower gears, as in stop-and-go traffic. The kids were
getting motion sick! Our interpretation is that the fuel mapping has
changed - and fuel is cut off too quickly when the driver lets up on
the accelerator. Furthermore, the mileage is much poorer than the
literature would suggest. We got 8-9 km/l on the highway, but the
specs suggest 11 km/l. I've not before encountered such a large
discrepancy between promise and reality in mileage.
Our dealer was very sympathetic, and attempted multiple tweaks in the
shop- but ultimately, we drew in customer relations at Subaru Canada.
Although they initially acknowledged there was a "driveability
problem" with the 2004, and they knew there was a "fix in the works",
they left the dealer to their own resources to resolve our problems.
Ultimately we moved to an automatic, paid the difference, and a little
more for "wear and tear". The dealer likely made no money on the deal.
They unloaded the car on a jeep owner who likely spends little time in
stop-and-go traffic. Overall, having the manufacturer leave the table,
after acknowledging a problem has me loose confidence in the product.
Has anyone else had similar observations with fuel mapping or
mileage, specific to the 2004 Outback?

My 2002 Leg. (manual transmission) does this, too. I don't think it's
related to the ECU programming, though. I seems like there's a bit
more "slop", for lack of a better term, in the Sube's drivetrain.
I've adapted my driving style accordingly...I ease off the accelerator
when possible.

Incidentally, did you ever notice a muted "pop" when letting up to
upshift? I think the _is_ related to ECU programming...it's as though
the ECU doesn't react fast enough to the closing throttle and a burst
of unburned fuel is rapidly combusted in the catalytic converter.

How do you like the auto. trans. on the Outback?

 

[R Jacobs]

My 2002 Leg. (manual transmission) does this, too. I don't think it's
related to the ECU programming, though. I seems like there's a bit
more "slop", for lack of a better term, in the Sube's drivetrain.
I've adapted my driving style accordingly...I ease off the accelerator
when possible.

Incidentally, did you ever notice a muted "pop" when letting up to
upshift? I think the _is_ related to ECU programming...it's as though
the ECU doesn't react fast enough to the closing throttle and a burst
of unburned fuel is rapidly combusted in the catalytic converter.

How do you like the auto. trans. on the Outback?

REPLY:
The Auto is a completely different car! No matter how you drive, you
can't replicate the jerk when letting off the gas (even letting off
slowly in the manual would give the sudden change in momentum). The
Auto is very smooth, and responsive, and drives well. I would have
prefered the control and style of a good manual transmission though.
I'm not sold on the slop in drivechain issue- in part because the
automatics don't do it, and because in a 4WD, you would expect the
momentum of the drivechain to push the engine more than in a 2WD - not
vice versa.
Given the behaviour of Subaru, I suspect they know there is a problem
with the 2004, but don't want to face the consequences of admitting
it.

 

[Verbs Under My Gel]

REPLY:
The Auto is a completely different car! No matter how you drive, you
can't replicate the jerk when letting off the gas (even letting off
slowly in the manual would give the sudden change in momentum). The
Auto is very smooth, and responsive, and drives well. I would have
prefered the control and style of a good manual transmission though.
I'm not sold on the slop in drivechain issue- in part because the
automatics don't do it, and because in a 4WD, you would expect the
momentum of the drivechain to push the engine more than in a 2WD - not
vice versa.
Given the behaviour of Subaru, I suspect they know there is a problem
with the 2004, but don't want to face the consequences of admitting
it.

I think the torque converter would insulate you from any slop in the
rest of the drivetrain.

 

[Kurt C. Hack]

Glad to know I'm not alone on this issue! I have driven manual
transmissions for many years, but in my 2002 OB it felt like I was still
learning! I had multiple issues with mine though. I had to have the
clutch actually replaced, under warranty, due to chattering problem
during cold or wet weather.

While I have changed my driving style to compensate for the problem,
when I want to drive a bit more aggressively I feel like I'm really
beating up on the drive train by the sudden jerks caused by this problem.

Has anyone actually questioned SOA on this issue? My dealer, of course,
tells me that this is completely normal for "any" car.

-Kurt

 

[Paul Pedersen]

My take on this is that they've programmed the car
to cut off fuel the minute you let up on the gas,
to cut down on pollution.

The problem is that the computer doesn't look first
to see that you've only let up slightly on the gas,
and not taken your foot completely off the pedal. It
then realizes its mistake and turns the gas back on.
It's a real pain.

There's a Maxima owner that has reported similar
problems on the net, though in that case the gas
apparently never comes back on.

I've been wondering what kind of danger this engine
behaviour puts one in on a very slippery surface,
like in winter, when you want to just let up very
slightly on the gas to slow down without sliding
and loosing control. With the gas being cut off
all of a sudden it's like you lifted your foot right
off the pedal, something I wouldn't do as I was
sliding towards the precipice.

One solution is to drive in a higher gear, which
minimizes the jerking, but leaves you outside the
proper power band. Another solution is to always
be accelerating, or at least maintaining a perfect
constant speed. It takes quite a bit of concentration
to balance everything on the fine point of proper
function. You end up leaving :lots: of room in front
of you in traffic.

It would be nice if Subaru came up with a reflash for
this, it really looks to me like the programmers screwed
up in their logic.

The problem is really severe on a new car, but gets
less after a few thousand miles. As it is, you have
to develop a whole new way of driving.

If any of you are about to test drive a manual Subaru,
try this : go along at a constant 3000 rpm for a bit then
very slowly lift you foot off the gas, like you wanted
to slow down just a bit, but otherwise want to keep a
constant speed. The gas will cut off all of a sudden,
then come back on a second later.

Like I said, a real pain.