Oxygen Sensor Code 21

Discussion in 'General Motoring' started by treeline12345, Aug 4, 2005.

  1. 1994 Voyager 3.0 liter V-6, Mitsubihi engine, almost 199,000 miles.

    This time when I noticed a Check Engine light as came to a red light.
    I thought, aha, this time, I shall look for a code. Thanks DS.

    An anomaly, the car stalled out while driving slowly around 20-30 mph,
    after about 5 minutes. It has done this in the past. Had 2 1/2 gallons
    of gas left in the tank. Oil is full. Don't know why it does this,
    usually upon starting. Happens about once a month or two or three. Just
    stalls out. So while coasting, put in neutral, and restart the engine.

    Checked the codes, pretty sure I saw 12 21 55. Not positive but pretty
    Assuming the 12 and 55 are the Start and Stop code, 12 for a battery
    disconnect within last 60 starts, which seems unlikely, but okay, it's
    common for the codes to start with a 12.

    So 21 is the:

    21 Oxygen sensor signal doesn't change (stays at 4.3-4.5V). Probably
    bad oxygen sensor

    I am wondering. Maybe low gas in the tank, too little pressure on the
    fuel pump might give this reading? The pump has to work too hard
    without fuel kind of boosting it a bit?

    A genuine bad sensor? Have had this car for only the last 30,000 miles
    and don't recall any repairs for sensors in the repair records though.
    Have to look again.

    I have the genuine, official Chrysler shop manual for this vehicle and
    a digital voltmeter, so could do a little poking around first. I heard
    the sensor is not too difficult to replace but to get the OEM part.
    Wonder what the price difference is. I replaced the thermostat with an
    OEM part which looked better made than the Slant and less likely to jam
    so worth three times the price, for less aggravation.

    Any ideas here? THe car had a tuneup, new plugs and wires and that
    valve, PCV? Maybe something else? Would the dealer have a scanner
    giving more codes and info? Have to see how if the Check Engine is
    going to come on all the time or not.

    Maybe throttle body cleaning, is that something I can inspect or is
    this one that is done by assumption? DS suggested that before but I
    have not noticed much in the way of stalling out after I posted that
    problem last year. My car apparently reads this newsgroup and behaves
    better after I complain!
    treeline12345, Aug 4, 2005
  2. treeline12345

    damnnickname Guest

    replace the 02 sensor and clean the throtttle body

    Glenn Beasley
    Chrysler Tech
    damnnickname, Aug 4, 2005
  3. It's not doing it. Just once the Check Engine light came on. Only once.
    The "21" code is stored but that would be stored in any case?

    If the oxygen sensor is bad, should not the Check Engine light be
    coming on while the car is running? Or so says the shop manual.

    What do you think? Does Autozone actually show the voltages the O2 is
    supplying or not supplying? Do they really have a full computer hookup?
    Seems unlikely but I have heard they will scan but don't know what they
    scan with.

    And replace it with the Bosch or with OEM? Or is the Bosch OEM? And
    this is the upsteam O2 sensor? It's the one that sits on top of the
    engine but I got confused when looking into carparts.com. 3 sensors
    with different part numbers but the same SKU! And 3 different prices.
    Wonder what the dealer charges. Somewhere in the same ballpark?

    Thanks for your comment. I'm just being a little cautious here until
    things lighten up and I can just give the minivan to the dealer and
    say, fix it, regardless!
    treeline12345, Aug 5, 2005
  4. treeline12345

    maxpower Guest

    When the 02 sensor does not switch for a certian amount of time the code
    is set, if it starts switching again the lite will turn off untill it acts
    up again
    Stay away from Auto zone to diagnois your vehicle, they sell parts
    The engine only has one sensor and I would use the OEM

    It's the one that sits on top of the
    Clean the throttle body and replace the 02 sensor and be on your way

    Glenn Beasley
    Chrysler Tech
    maxpower, Aug 5, 2005
  5. How old is the O2 sensor?
    Probably. Replace it. It'll probably fix your stalling problem and
    certainly improve your mileage. Don't use a Bosch O2 sensor; they fail
    early and often. Pick an NTK, Mopar, ACDelco or Standard-BlueStreak. The
    O2 sensor socket (with the slot down the side) makes it easy.
    No (but do keep on top of the fuel filter replacement schedule. Every 20k
    to 30k miles is good.)
    Be advised that the O2 sensors get slow/lazy as they age, so even if you
    see changing voltage across the O2S, if it's old, replace it.
    Cleaning the T-body and AIS is a good idea every once in awhile on the

    Daniel J. Stern, Aug 5, 2005
  6. Depends on the emissions package (Federal/Canada or California), engine,
    vehicle and model year.
    Do not rely on Autozone for diagnostics.
    No, they have ignorant Burger King rejects selling parts.
    Mopar, NTK, ACDelco, Standard-BlueStreak, NOT BOSCH.
    The one and only in that vehicle.
    Taking an 11-almost-12-year-old vehicle to the dealer is begging to be
    Daniel J. Stern, Aug 5, 2005
  7. treeline12345

    tim bur Guest

    really, raped !!!hmmm listing to you will send them down the wrong road when a
    sensors voltage is high like it showed at 4.5 volts that usually means the
    wire is cut or the sensor is unplugged
    oh by the way have the feds finalized the recall form the wonderful design you
    did on the rs mini vans headlites that just shut off for no reason
    tim bur, Aug 6, 2005
  8. The car was manufactured in Windsor, Canada; however, the market code
    is for the United States, according to the VIN and the Body Code Plate.

    So it's most likely following USA Federal protocols? It appears too.
    The Check Engine light has come on while the vehicle is being operated
    twice in one week now with the Oxygen Sensor code of 21.

    One anomaly on the Body Code Plate. For the transaxle codes, I have
    This is not listed in the shop manual. Could they have just made a
    mistake in stamping out the Body Plate Code? The presumably correct
    code is DGL = 4-speed Electronic Automatic Transaxle or A604 which I
    have. The manual does not like anything like DGB which I have.

    The other odes are all for automatic or manual transaxles, not the
    electronic transaxle or transmission, like DDM DGM DGC.
    Thanks, so far locally I have found a Borg-Warner I can order from an
    auto supply store for $51 and the OE or Mopar, presumably, for $102
    from the dealer.

    One does need to practice safe automotive repair and be wary of too
    intimate a relationship with the mechanic :)
    treeline12345, Aug 7, 2005
  9. I can't tell for sure. I cannot find anything in the repair records of
    my friend for the last 7 years or 120,000 miles - so it's probably that
    old for sure, if not OE. I also cannot locate the sensor yet to
    identify if it's OE or a replacement. In the manual it looks so
    obvious, sitting on the exhaust manifold all by itself. Is it possibly
    under the air filter in the rear near the firewall & that must be
    removed to see it or I am just missing it?
    That's good to hear. The manual says to have a Snap-On YA8875 socket
    which was a bit discouraging unless there's something like that I
    already have. Ill feel better once I locate it.

    The manual says to release the pressure but is that necessary for just
    the throttle body? Does not seem so since fuel lines are not connected
    to it that I would remove? I asked the service manager at the
    dealership and he said don't bother with releasing pressure if not
    messing with fuel lines.

    But releasing the pressure, if I need to, is done by removing the gas
    cap releases a lot. Then there's also the disconnection of the injector
    wiring harness (visions of ruining it by disconnecting it), then
    connect a jumper wire to A142 circuit terminal of fuel rail harness and
    the other end to 12+ volts, and another to a good ground and then to
    the injector terminal for 2-3 injectors. Do mechanics do all of this as
    says in the manual?

    I gather one could clean the throttle body with just disconnecting that
    hose going to it. I was suprised to see Holley there, thought of the
    old Holley carburetors. But to get the AIS motor to clean, one would
    have to disconnect the throttle body? Unbolt it and so on or somehow
    unscrew the AIS motor?

    If I get to it, I think you recommended Berryman's B12. How does that
    compare with the official de-carb cleaner from the dealer 4318001AB? Is
    it like the sensor, 1/2 the price but just as good if not better?

    Hmmm, thanks, don't think this has been done in years. Now here's where
    I would have to release the pressure, once I find it. Looks easy in the
    treeline12345, Aug 7, 2005
  10. Right -- the relevant info is the market for which the vehicle was built,
    not the plant where it was built.
    It would have to, to have been legal for sale in the US as a new vehicle.
    The underhood VECI (Vehicle Emission Control Information) label will
    clearly state whether it is a Federal, California, or Canada vehicle.
    Body code plate errors are rare; service manual info omissions are common
    Borg-Warner = Dana, that's a fine part. Mopar = NTK, also a fine part, but
    overpriced via the dealer.

    www.ngk.com isn't the corporate site; it's a vendor. They show an OE
    sensor for all of $44.85.

    Daniel J. Stern, Aug 7, 2005
  11. It says the vehicle conforms to the USA EPA and the State of California
    for light-duty trucks at all altitudes.

    So it is California then and Federal by default if California is more
    strict than any other state? It has passed inspections in New Jersey
    and Pennsylvania so it seems it's good to go anywhere.

    Thanks for finding the Original Equipment part for the same price as a
    Bosch. That's also saving of 55% for an OE part!
    treeline12345, Aug 7, 2005
  12. State emission inspection results are not an indication of a vehicle's
    compliance with any particular emissions certification requirement
    (Federal, Canada, California, etc.)

    Daniel J. Stern, Aug 7, 2005
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