Re: DML O2S (Was: leaking power steering)

From: Biff Byrum (bbyrum9@foothill.net)
Date: Mon May 18 2009 - 16:50:15 EDT


It sounds like it was the fore sensor. I may have just gone through that
myself, but I never bothered pulling the codes. I knew what I needed.

Return values for the fore sensor are supposed to be in the range of 0.2 to
0.8 volts. Several years ago I put one in my 95 that went bad. The smog guy
told me he had never seen one that was returning line voltage. (5.2 volts)
And it was virtually undriveable when it was doing that.

On my 98 I knew I needed a cat, and I didn't like the exhaust coloring. On
my 98 3.9 that slotted socket is unuseable. I just found a 7/8 combo wrench
and it got right at it.(From the driver's side)

I guess the guy I bought it from never bothered to change it out, even
though it had 134 on the clock when I got it. With the new Cat and fore O2S,
it was as clean as a baby, even with 233 on it now. The Nox values were 74
at 15mph and ZERO at 25 mph.

As for keeping that aft sensor, probably so. The fore sensors are rated at
about 80 to 100K, but as Bernd has said, does the aft sensor even affect the
pulse width algorithm? It's stated task is to measure Cat efficency. But
what the heck? Those are good prices. I paid a little more for mine. Biff
Byrum

----- Original Message -----
From: <jon@dakota-truck.net>
To: <dakota-truck-moderator@bent.twistedbits.net>
Sent: Monday, May 18, 2009 1:10 PM
Subject: Re: DML: Re: Re: Re: Re: Leaking power steering fluid

>
> Tom Coulter <metalshop@optonline.net> wrote:
>
>> Thanks for your notes, Jon, though I wish I'd heard sooner. Based on
>> Brian's earlier post, I went ahead and visited oxygensensors.com and
>> ordered
>> BOTH sensors: Walker, for $41.90 (front) and $54.90 (rear). I posted
>> "Seems like the next step is to replace both and see if the nagging code
>> clears." and hadn't heard anyone "stop" me.
>
>
> Sorry about that - can't catch 'em all! :-) It didn't dawn on me
> until then that you had mentioned replacing both sensors. I'm not an
> encyclopeda or anything, but I didn't recall an O2 sensor code which
> flagged both at once. (This makes sense from a diagnostic perspective
> also - with one code for each sensor the mechanic knows which one is
> the problem.) Sorry, it just didn't strike me until I was replying to
> your last post there.
>
>
>> BTW, the local dealer wanted
>> $110 apiece for each one (MOPAR). All local parts stores carried the
>> dubious Bosch sensors (oddly, the AutoZone guy agreed w/ the bad karma
>> toward the Bosch units).
>
>
> Ouch. :-) And people wonder why some folks refer to them as
> "stealerships". ;-) The exact same part is $30 cheaper at Wyckoff.
> I must admit that I don't know how it works behind the scenes, but I
> would expect each dealership pays about the same for Mopar parts when
> buying from Chrysler...
>
>
>> I appreciate your scoping OEM at Wyckoff Chrysler but, as I said, I went
>> w/
>> the Walker units (they're on the way here).
>
>
> On the plus side, that's a really good price for the sensors, so
> even if you don't need the downstream one right away, chances are
> you'll need it eventually. (And with inflation about to skyrocket,
> its probably cheaper to buy it now than later anyway...) ;-)
>
>
>> Interesting that you thought it was only the UPstream sensor. In my
>> earlier
>> post, I said:
>> Now let's turn to the Check Engine message I mentioned. I pulled the
>> code
>> and it's P0132 (O2 Sensor Circuit High Voltage). Sensor 1 & 2 on Bank 1
>> read "1000V 0% S.T. fuel trim". This strikes me as a possible short.
>
>> "Sensor 1 & 2 on Bank 1"
>
>> This seemed (and still seems) like TWO sensors, though the error message
>> relayed to the scan tool may be cryptic.
>
>
> Yep, I don't believe that description is correct. The part about
> high voltage is right, but P0132 is a standard OBDII code which refers
> to bank 1, sensor 1, and a manufacturer can't just change the meaning
> of the code without violating the standard. Possibly the database in
> your code reader has a typo or is just incorrect.
>
>
>> You said:
>> If the downstream sensor were doing the same thing you would have gotten
>> a
>> P0138 code as well.
>
>> Very interesting, and you may well be right, but this isn't what I got;
>> only
>> the P0132 code that, when I went to the test tab, gave the info I listed
>> above.
>
>
> Yep, P0138 is the same thing as P0132 except it refers to bank 1
> sensor 2, which on a Dak with only 2 oxygen sensors is the downstream
> (post cat) sensor.
>
>
>> Where does that leave us? Install the upstream sensor and see if the
>> code
>> clears? If it does, hang the other one on a nail for next time?
>
>
> Yep, if 'twere me, that's exactly what I would do. You could check
> into the possibility of returning the other sensor or eBaying it or
> something, but you'll probably be out some money either way, and as I
> mentioned earlier, even if you don't need the downstream sensor now,
> if you hang onto the truck long enough, you'll need to replace it
> eventually.
> -Jon



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