Oxygen sensor location?

[cardiac]

Hi guys,

My 1996 Ford E-150 with the 5.8 liter started running a little rough and the fuel mileage was cut in half. Then I got the "check engine" light. Threw the OBD II scanner on there and the only code I can pull says the Oxygen sensor in "Bank 2 Sensor 2 Location" is malfunctioning. Does anyone know which one of the three oxygen sensors this is? Napa has them in stock but they are also not quite sure which one is which, because there are 2 different sensors........

Thanks a bunch,

Bob

 

[BaDave]

If it only has three o2 sensors than it will be the one after the converter.Or the one the farthest away from the motor.An so ya know in most cases when they refer to o2 sensors rule of thumb is bank 1 is the side that the #1 cylinder is located an bank 2 is the other side.Sensor 1 would be the sensor before the cat. converter an sensor 2 would be after the cat.

 

[Zenmervolt]

Originally posted by: BaDave
If it only has three o2 sensors than it will be the one after the converter.Or the one the farthest away from the motor.An so ya know in most cases when they refer to o2 sensors rule of thumb is bank 1 is the side that the #1 cylinder is located an bank 2 is the other side.Sensor 1 would be the sensor before the cat. converter an sensor 2 would be after the cat.

If there are only three sensors, the third would be after the pipes come together and would need no bank information in the code. Why do they specify "Bank 2" then?

ZV

 

[cardiac]

Thanks guys. I was "assuming" (Yeah, I know about assuming) that it would be after the converter as I would think the front Y pipe sensors would be bank 1 sensor 1, and bank 2 sensor 1.

Zenmervolt, I don't kow why they would do this. Any other codes I've pulled from different vehicles were actually pretty specific. I guess I'll go ahead and get this sensor and change it....

Thanks,

Bob

 

[imported_Truenofan]

i thought banks are the sides of the engine.....bank one is one side, bank two is the other side. get a Haynes manual to find it, those usually get you where you need to be.

 

[drnickriviera]

It's the one after the cat. Toyota/Lexus labels them the same way. I imagine that's the way they labeled them for OBDII. I'd go ahead and replace all 3. Actually i'd get the code and look it up in the factory manual to make sure there is nothing else that could be the problem.

 

[cardiac]

Originally posted by: drnickriviera
It's the one after the cat. Toyota/Lexus labels them the same way. I imagine that's the way they labeled them for OBDII. I'd go ahead and replace all 3. Actually i'd get the code and look it up in the factory manual to make sure there is nothing else that could be the problem.

Uh no. Not going to replace all three. Too expensive. I'm pushing 200k on that van and it's the original motor/trans. I'm going to be getting rid of it this fall, so I just want to maintain it as cheaply as I can. Drnick, I appreciate the info. I would replace all three if I was going to keep it. I did replace both front Y-pipe sensors about 60k ago.....

Thanks guys,

Bob

 

[Demon-Xanth]

Zemmervolt:
In the case of my truck, it has four, one before and after each pre-cat (yes, I have three cats). I would guess that the code says bank two to fit into the standard OBD-II code set. Even though there would be no "sensor 2, bank 1" sensor.

OP:
It's the one behind the cat.

 

[Zenmervolt]

Originally posted by: Demon-Xanth
Zemmervolt:
In the case of my truck, it has four, one before and after each pre-cat (yes, I have three cats). I would guess that the code says bank two to fit into the standard OBD-II code set. Even though there would be no "sensor 2, bank 1" sensor.

Yeah, with four it would make sense, but I can't figure it out with only three.

ZV

 

[Demon-Xanth]

List of O2 sensor related codes:

P0130 O2 Sensor Circuit Malfunction (Bank 1 Sensor 1)
P0131 O2 Sensor Circuit Low Voltage (Bank 1 Sensor 1)
P0132 O2 Sensor Circuit High Voltage (Bank 1 Sensor 1)
P0133 O2 Sensor Circuit Slow Response (Bank 1 Sensor 1)
P0134 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1)
P0135 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)
P0136 O2 Sensor Circuit Malfunction (Bank 1 Sensor 2)
...
P0141 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)
P0142 O2 Sensor Circuit Malfunction (Bank 1 Sensor 3)
...
P0147 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 3)
P0150 O2 Sensor Circuit Malfunction (Bank 2 Sensor 1)
...
P0155 O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)
P0156 O2 Sensor Circuit Malfunction (Bank 2 Sensor 2)
...
P0161 O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 2)
P0162 O2 Sensor Circuit Malfunction (Bank 2 Sensor 3)
...
P0167 O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 3)

They simply chose to call it bank 2 instead of bank 1. Just an arbitrary decision.

 

[Zenmervolt]

Originally posted by: Demon-Xanth
They simply chose to call it bank 2 instead of bank 1. Just an arbitrary decision.

I understand that it's an arbitrary decision, and I'm agreeing with everyone that it's the sensor after the cat. It just seems illogical to have any bank information for that sensor in a 3 sensor setup.

It would be like getting a code on my Volvo (single O2 sensor) that said it was the "Bank 1, position 1" sensor. It's the only sensor there is, why put the additional information in there?

I guess it's probably because they use the same error codes on all engines and it has to be able to handle instances where there's a true dual exhaust, but it still seems illogical.

ZV

 

[Demon-Xanth]

That's because as listed above, it's the standard, non-vehicle specific code. The codes above and what they translate to are part of the OBD-II spec, not a manufacturer's page.

 

[Zenmervolt]

Originally posted by: Demon-Xanth
That's because as listed above, it's the standard, non-vehicle specific code. The codes above and what they translate to are part of the OBD-II spec, not a manufacturer's page.

Gotta love generic messages.

ZV

 

[cardiac]

Originally posted by: Demon-Xanth
List of O2 sensor related codes:

P0156 O2 Sensor Circuit Malfunction (Bank 2 Sensor 2)

They simply chose to call it bank 2 instead of bank 1. Just an arbitrary decision.

This is the code I get.

Thanks for the extra info, Demon-Xanth...

Bob

 

[Demon-Xanth]

A good way to test which one it is, btw. Is to unplug them one at a time and see if any new codes get thrown up.

 

[cardiac]

There is also a resistance test you can do with 02 sensors....Get them up to operating temp, then unplug them and check the resistance with a DVM across the leads. I think it's supposed to be between 3-30 ohm's resistance for my sensors.... Others are different values.... Good idea about unplugging them one at a time...

Bob

 

[cardiac]

Plugged in the scanner to check one more time before I went and picked up an O2 sensor. Now, it isn't even showing the PO156 code, but showing a PO171! This shows as Bank One Lean Condition. So now, I'm going to have to figure out what is causing the lean condition, whether it is the MAF, or a leak somewhere......

Crap.....

Bob

 

[Demon-Xanth]

Check the O2 sensors for chafed insulation on the wires leading to it.

 

[drnickriviera]

http://www.motorcraftservice.c...lt.asp?pageid=&gutsid=
Go here and buy a subscription to get the workshop manual

 

[alpineranger]

on my vehicle (this should be consistent, as that's one of the points of ODBII), the second sensor for each bank is only there to monitor the performance of the catalyst. Your car should not run any worse with this sensor not working, unless your catalyst is shot, in which case you just wouldn't know.

edit: the upstream, pre cat sensor will cause all sorts of problems if it isn't working, because then the computer won't know how much fuel to give to to the engine in open loop operation (usually all the time except for startup and full throttle operation). It'll go into a fail safe mode and dump more fuel into the engine, just to be safe. Fuel economy and driveability takes a crap as a result. To find this sensor, simply follow the exhaust header from the cylinder head to the catalyst. it should be somewhere along that stretch.

 

[cardiac]

Thanks for the extra info, guys. I did clean the MAF and reset the OBDII, and I haven't had a check engine light since. Seems to still run fine. Only thing I noticed before was that my fuel mileage went to hell....Haven't driven it enough to know if that improved or not...

Bob