Oxygen Sensor Code 21

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
sure.
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!

 

replace the 02 sensor and clean the throtttle body

Glenn Beasley
Chrysler Tech

 

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!

 

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

 

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
3.0.

DS

 

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
raped.

 

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

 

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
DGB.
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

 

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
manual.

 

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.

DS

 

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!

 

State emission inspection results are not an indication of a vehicle's
compliance with any particular emissions certification requirement
(Federal, Canada, California, etc.)

DS