Code P0141 -Engine Light On-O2 Sensor

[ampenergy88]

Hello,
My 99 Tahoes Engine light went on yesterday morning.I took it to the local Advanced Auto Parts store to get My truck scanned and clear the engine light.
The clerk said it was Code 0141 O2 Sensor Bank 1 Sensor2.

He cleared it and it went back on the next day. Does anyone know where my o2 sensor is located?
Do I have 2 of them?
Are they hard to replace? Any info would be appreciated.
Thank you!

 

[Sepiroth]

Driver's side of the engine, second O2 sensor in the exhaust pipe.

 

[ampenergy88]

Is the Sensor Bank 1 Sensor2 in the Exaust Pipe?What does the Bank 1 mean?
Is hard to get at?
Thanks

 

[Sepiroth]

Banks are referring to the sides of the engine. Since you have a V-design type engine, you have 2 banks.

 

[ampenergy88]

Does that mean I have 4 O2 Sensors? Or just 3 and one in the exhaust?

 

[Sepiroth]

I want to say 4 but I may be wrong. Part of me thinks you have 3. One on each bank, those are called pre cat O2, and one post cat

 

[fyremanpat]

You have 4 O2 sensors total. 2 upstream (before cats) and 2 downstream (after cats). The later Tahoes were made with true dual exhaust all the way to the muffler. Right bank is passenger side and left bank would be drivers side. O2 sensors are relatively easy to replace but can be pricey. I recommend replacing all 4 though. Also try cleaning you MAS with the actual MAS cleaner...I swear by it after using it. Hope this helps.

 

[DefEddie]

just some info for the masses.

Bank 1 on an OBDII vehicle is always the bank with cylinder 1,coincedentally this always falls on passenger side of Ford and Chevy firing orders.
Bank 2 is the other bank.
Each bank has it's own Sensor 1
Each catlytic convertor has it's own sensor 2
If you got two convertors you should have 2 02 sensors after cat. If you have one cat then you will only have one 02 sensor after it(sensor 2)
Pretty sure you got two cats though.

 

[Sepiroth]

just some info for the masses.

Bank 1 on an OBDII vehicle is always the bank with cylinder 1,coincedentally this always falls on passenger side of Ford and Chevy firing orders.
Bank 2 is the other bank.
Each bank has it's own Sensor 1
Each catlytic convertor has it's own sensor 2
If you got two convertors you should have 2 02 sensors after cat. If you have one cat then you will only have one 02 sensor after it(sensor 2)
Pretty sure you got two cats though.

Are you sure? It is my belief that on Chevy LS engines Bank one is on the driver's side. Ford's Bank one is on the passenger side.

 

[blk87brd]

I certainly hope DefEddie is wrong, because every GM I've owned has #1 cylinder on the driver's side. I'm in Canada and I know that American and Canadian models are different but I don;t think they are that different. The two I own presently (5.7 & 5.3) have #1 on the driver's side.

 

[treepete]

either way, the O2 can be replaced. I think mine were about 75$ each for my year.

Spray it with PB blaster, let it soak, and you should be able to take it out with a wrench.
wipe the area clean, and carefulle screw the new one into place.

I agree that if you have one failing, you might get a pre-fail condition with your scanner on the other ones. if you can swing it, replace them all simultainously.

 

[DefEddie]

doh!
sorry,was up way to late last night. cyl 1 is on the driver side on chevy,I haven't had my head under my projects in so long i've lost my mind.
That's what being a Ford tech with a GM hobby will do to you

 

[IronMan4Real]

Just got same code this morning myself. buuuuuut this is the first winter this 99 Tahoe has ever seen. And yesterday its first snow fall(its from Florida). I got a code P0141 and P0141 P. I am not sure why a second code and why the P. Maybe its supposed to Piss me off which it did. Im thinking the new found elements didnt help. lol
I cleared it with my cheap code reader. If it comes back on ill take it to a tech.
I just switched the gas cap to a locking one as it was $128 to fill and didnt want my gas stolen. I thought maybe at first that is what caused the engine light to come on. Evap code for gas cap not sealing correctly. I took it off my 95 Caprice. But no evap code so that aint it. My code reader is el cheapy so no hope of determining or diagnosing further which O2 it is.

 

[lesterl]

Dont know why you got the second code...... I have had the heater code pop up from time to time, it will be back, just means the sensor will be slower to warm up, I ignore mine for now.... P0141 is Heater circuit Bank 1, sensor 2 which is the one right AFTER the CAT on the drivers side exhaust pipe, not used to calibrate fuel trims....

 

[IronMan4Real]

thanks Lester 1
Ill ride it out for now but 99% of time I am on top of stuff...Christmas coming up.