P0031 - Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 1 Sensor 1)

[Yousuf Khan]

I just got a Check Engine light come on. I got the above code after
hooking my OBD-II code checker to it. Also interestingly, after getting
this code, my cruise control light started blinking, and the traction
control light came on full time.

Is this one of those glitches that can sometimes happen? Should I reset
the the code, and things will get back to normal? It just happened out
of the blue one a couple of days ago after I just started the engine,
and it was working just fine half an hour earlier.

Yousuf Khan

[Bob Bailin]

"Yousuf Khan" <bbb...@spammenot.yahoo.com> wrote in message
news:2qudnX1kTs9R00bL...@giganews.com...

It may not be the O2 sensor (you can test the resistance).

Check out the following article (from googling subaru p0031):

http://forums.nasioc.com/forums/showthread.php?t=1784439

Bob

[Yousuf Khan]

On 05/03/2016 4:57 PM, Bob Bailin wrote:
> It may not be the O2 sensor (you can test the resistance).
>
> Check out the following article (from googling subaru p0031):
>
> http://forums.nasioc.com/forums/showthread.php?t=1784439
>
> Bob

Yeah, I saw that, but I think that might be a little premature to start
suspecting that right away.

Any idea why the cruise control and traction control went out with it?
What do they have to do with the O2 sensor?

Yousuf Khan

[cl...@snyder.on.ca]

I'd be looking for a common ground or power point - most likely a bad
ground if resetting the code doesn't solve the multiple failure issue.

[weelliott]

The Cruise control goes away when you get a CEL. I think it's Subaru's way of punishing you for having a CEL. Too bad there is not way of punishing subaru fro creating cars that so easily have a CEL.

[Yousuf Khan]

On 06/03/2016 3:44 AM, weelliott wrote:
> The Cruise control goes away when you get a CEL. I think it's Subaru's way of punishing you for having a CEL. Too bad there is not way of punishing subaru fro creating cars that so easily have a CEL.

In my old 2000 OBW, I've had CEL's and I've never had cruise control go
away because of it (the OBW didn't have traction control though). This
is actually my first-ever CEL on my Tribeca, so I've never seen this
behaviour before. Maybe Subaru added this feature between 2000 and 2008?

Yousuf Khan

[Yousuf Khan]

On 05/03/2016 9:34 PM, cl...@snyder.on.ca wrote:
> I'd be looking for a common ground or power point - most likely a bad
> ground if resetting the code doesn't solve the multiple failure issue.

Weeliott seems to think that this is default behaviour whenever you get
any kind of a CEL.

Does anyone have any opinions on getting aftermarket O2 sensors? The
Subaru parts range from C$244+, whereas an aftermarket part seems to go
from U$79+ (C$105) to C$140. Also the cheapest one is available through
Amazon.com, but it'll take maybe 3 weeks to be delivered to me, is that
too much time to wait, and should I just source it locally?

Yousuf Khan

[Darryl Johnson]

My wife's 2008 Impreza throws up a CEL whenever
she doesn't get the gas cap tight enough. And the
cruise control will not engage until we stop and
re-tighten the gas cap.

It's a royal PITA when we're on a closed highway
where stopping for anything other than emergencies
is frowned upon.

[Bob Bailin]

"Yousuf Khan" <bbb...@spammenot.yahoo.com> wrote in message

news:1eKdnUc_kcRO70HL...@giganews.com...

A good reason to try to diagnose the existing sensor first. Nothing quite
like installing a new, expensive part and nothing changes.

I'm wary of most aftermarket sensors. If the OEM part is too pricey, try an
aftermarket OEM supplier like Denso for Japanese cars. If you have a 2008
Tribeca, the p/n is 234-9047 for the upstream sensor and it's C$166 on
Amazon.

[cl...@snyder.on.ca]

It has been my experience generally that you end up paying the same
or more when you use aftermarket sensors as OEM because the
aftermarket direct fits are just about as expensive as the OEMs (if
you get good ones) and if you buy universals you will end up replacing
it again - and end up going to OEM or direct fit eventually to solve
the problem anyway.

The OEM is not made by Subaru in the first place - so if you can get
the direct fit "aftermarket" part made by the same supplier as OEM you
are all set (I believe Subaru used NGK sensors as OEM) - but generally
the price difference is not huge.

[cl...@snyder.on.ca]

Teach her to put the gas cap on properly.. Also, putting the gas cap
on properly will not turn off the CEL immediately - it has to go
through the evap monitor test section of the drive cycle - so putting
the gas cap back on will generally NOT give you cruise control back
right away.

[Darryl Johnson]

She'd had the car in for inspection because you
*really* have to lean on the cap as you turn it.
Even then, you have to turn in until it has
clicked at least a dozen times. And sometimes even
that isn't enough. Personally, I suspect the cap
itself, or the top of the fuel pipe, is "off". On
my own car (not a Subie), I can almost finger
tighten the gas cap to one click and I'm good to
go. But the dealership insists nothing is wrong.
<sigh>

Also, putting the gas cap
> on properly will not turn off the CEL immediately - it has to go
> through the evap monitor test section of the drive cycle - so putting
> the gas cap back on will generally NOT give you cruise control back
> right away.
>

Don't I know it. We stop for gas, have to stop
again to reset the gas cap. Then stop again at the
next rest stop to shut the engine down and restart
it. And, usually, again at the rest stop after that.

As I say, I royal PITA.

[cl...@snyder.on.ca]

On Sun, 6 Mar 2016 17:51:37 -0500, Darryl Johnson

Regardless what the dealer says, you have a problem.Check for any
sign of rust on the top of the filler neck. If it looks perfect, try a
new cap. There should not be that much effort required to seal the
fuel system.

[dsi1]

On 3/5/2016 10:44 PM, weelliott wrote:
> The Cruise control goes away when you get a CEL. I think it's Subaru's way of punishing you for having a CEL. Too bad there is not way of punishing subaru fro creating cars that so easily have a CEL.
>

If you're a fan of the CEL, you couldn't do better than getting a VW or
Audi - they have so many air and vacuum hoses that get brittle and crack
and leak that you can bet you're gonna be driving around with one. CELs
forever! ;)

[cl...@snyder.on.ca]

Damned german rubber ---among a dozen or more things I hate about
"wiener wagons"

[dsi1]

My mechanic is afraid to work on my Passat 1.8T 4Motion wagon. I've been
buying Chinese made plastic hoses and fittings to replace in my spare
time. It's a work in progress. The engine mounts will probably go any
day now so I'll be on the lookout for that. I'll also have to replace
the diverter valve and maybe the secondary air pump and hoses. I'm
hopeful that the turbo will hold up. Other than that, the engine's fine!

Yesterday, I saw a guy in the supermarket with the car hood up so I
asked him if he was having trouble. He said he just bought the Audi A4
for his daughter to drive to school and he was checking fluid levels.
The car is pretty much the same as mine so I told him to check the power
steering level and I'd top it off for him since I just bought a can of
special German power steering fluid imported from the Fatherland which
cost $23 dollars per liter. Thank god it was OK since that stuff is
expensive!

Anyway he had automobile mayo in the coolant tank so that's very bad
news. I didn't say anything because he seemed rather proud of the car
and who am I to spoil the moment? :)

[cl...@snyder.on.ca]

The chinese rubber and plastic is often pretty awfull stuff too, but
not as bad as the german stuff - generally speeking.

[dsi1]

I can't imagine that the Chinese parts are going to be much worse than the OEM parts made by Bosch or Hella or whatever. They look pretty good to me, actually. :)

[Yousuf Khan]

On 06/03/2016 3:44 AM, weelliott wrote:

> The Cruise control goes away when you get a CEL. I think it's Subaru's way of punishing you for having a CEL. Too bad there is not way of punishing subaru fro creating cars that so easily have a CEL.

Yeah, called a bunch of dealerships and they confirmed that by default
they turn off cruise and traction controls on vehicles that get a CEL
come on.

Yousuf Khan

[Yousuf Khan]

On 06/03/2016 5:19 PM, Bob Bailin wrote:
> A good reason to try to diagnose the existing sensor first. Nothing
> quite like installing a new, expensive part and nothing changes.
>
> I'm wary of most aftermarket sensors. If the OEM part is too pricey, try
> an aftermarket OEM supplier like Denso for Japanese cars. If you have a
> 2008 Tribeca, the p/n is 234-9047 for the upstream sensor and it's C$166
> on Amazon.

Yeah, I found a Bosch replacement part on Amazon.com (not Amazon.ca) for
about C$105. The only problem is that they can't deliver it for at least
3 weeks. Should I take a chance with not having this part for 3 weeks or
more, or should I go with a locally sourced part? Canadian Tire is
selling one for C$140, don't know the brand though, but they can have it
by the end of the week.

I'm thinking that I'm not in any danger of destroying the catalytic
converter because this car has 4 sets of O2 sensors altogether, because
there are two banks of cylinders. The other bank's O2 sensors are both
working. I'm thinking that if whatever emissions are happening on one
bank, roughly the same sort of emissions are occurring on the other bank
too. So if anything starts to go off, it'll get detected by the working
bank for the time being. Should I take a chance on this line of logic?

Yousuf Khan

[cl...@snyder.on.ca]

Your assumptionis wrong. Replace the sensor ASAP. I think Canadian
Tire is selling NGK - ask - they can usually tell you.

[cl...@snyder.on.ca]

On Tue, 8 Mar 2016 00:48:28 -0800 (PST), dsi1 <dsi...@yahoo.com>
wrote:

I didn't say they were worse. I said they were crappy but "not as
bad as the German stuff"

[dsi1]

I never said you said anything. The Chinese parts look to be about the
same as the German stuff. Of course I can't say if they'll be more
durable than OEM German parts because that's going to take years to find
out. OTOH, my guess is that many of the OEM parts are not made in
Germany but in countries in Europe able to produce the parts for dirt
cheap.