O2 sensor locations please

Tiny
DESIREE_2007
  • MEMBER
  • 2005 CHEVROLET TRAILBLAZER
  • 74,000 MILES
I have the vehicle listed bove l6 4.2. It is throwing code p0140 which is o2 sensor bank 1 sensor 2, but when my husband and I got the part it looks like it is sensor 1 according to location so where is the sensor 2 exactly located? I am just trying to make sure I am not confused and we are replacing the right sensor. I mean he went off the code to find the part. I guess I am just paranoid it is not the right one because I always assumed it was under the passenger side front door. First of all, bank 1 is the drivers side. And yes, it would be under the drivers door, not through the wheel well?
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Saturday, June 2nd, 2012 AT 1:35 AM

27 Replies

Tiny
ASEMASTER6371
  • EXPERT
Here is a guide to help you get the oxygen sensor changed out and the sensor locations below:

https://www.2carpros.com/articles/how-to-replace-an-oxygen-sensor

Check out the diagrams for both engine (below). Please let us know if you need anything else to get the problem fixed.

Cheers, Roy
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Saturday, June 2nd, 2012 AT 1:40 AM
Tiny
DESIREE_2007
  • MEMBER
Thank you, it is just what I needed. I love this site.
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Saturday, June 2nd, 2012 AT 1:46 AM
Tiny
ASEMASTER6371
  • EXPERT
Good to hear. Please use 2CarPros anytime we are here to help.

Cheers, Roy
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Saturday, June 2nd, 2012 AT 1:48 AM
Tiny
ZEUS6905
  • MEMBER
  • 2005 CHEVROLET TRAILBLAZER
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 160,000 MILES
Where are they located and how do I change them?
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Wednesday, June 13th, 2018 AT 3:53 PM (Merged)
Tiny
HMAC300
  • EXPERT
There is one in front of converter and one in back depending on code that would be the one that is in need of replacement maybe. There is a tool auto parts probably rents it. Here is a link on how to do it:
https://www.2carpros.com/articles/how-to-replace-an-oxygen-sensor
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Wednesday, June 13th, 2018 AT 3:53 PM (Merged)
Tiny
STEVE W.
  • EXPERT
Why do you think they need to be changed? Unless they test faulty or sluggish they are likely fine. Do you have a code or codes suggesting a problem? What are they? How about driveability issues? O2 sensors get changed for a lot of reasons when they are not the actual problem.
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Wednesday, June 13th, 2018 AT 3:53 PM (Merged)
Tiny
KEN WRIGHT2
  • MEMBER
  • 2004 CHEVROLET TRAILBLAZER
  • 4.2L
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 148,658 MILES
Where are b1 up flow and down flow sensors located?
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Wednesday, June 13th, 2018 AT 3:53 PM (Merged)
Tiny
STEVE W.
  • EXPERT
Only has two O2 sensors. One is on the exhaust manifold near the passenger side rear of the engine on the curved area. The other is in the exhaust system behind the converter.
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Wednesday, June 13th, 2018 AT 3:53 PM (Merged)
Tiny
DAMORANCLAN
  • MEMBER
  • 2004 CHEVROLET TRAILBLAZER
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 116,000 MILES
Can you tell me where I would find the Post-converter sensor, bank 1 sensor 2 on a 2004 Chevy Trailblazer EXT? I got the error code P0141 and purchased sensor to replace it. I replaced the sensor for error code P1133 yesterday. Thanks for the help.
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Tuesday, January 15th, 2019 AT 5:39 PM (Merged)
Tiny
DOCFIXIT
  • EXPERT
Left exhaust pipe after CAT.
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Tuesday, January 15th, 2019 AT 5:39 PM (Merged)
Tiny
SMH5362
  • MEMBER
  • 2004 CHEVROLET TRAILBLAZER
  • 10,600 MILES
Diagram of engine compartment for O2 senor replacement
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Tuesday, January 15th, 2019 AT 5:39 PM (Merged)
Tiny
SMH5362
  • MEMBER
  • 2004 CHEVROLET TRAILBLAZER
  • 10,600 MILES
Need diagram of engine
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Tuesday, January 15th, 2019 AT 5:39 PM (Merged)
Tiny
TAWILLIAMS@WHITESHIELD.CO
  • MEMBER
  • 2001 CHEVROLET TRAILBLAZER
2001 Chevy Trailblazer 6 cyl Four Wheel Drive 103000 miles

I am looking for the location of the o2 sensor
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Tuesday, January 15th, 2019 AT 5:41 PM (Merged)
Tiny
RASMATAZ
  • MEMBER
You got 2 one in front of the catalytic converter and one after it
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Tuesday, January 15th, 2019 AT 5:41 PM (Merged)
Tiny
LEVERT SHELL
  • MEMBER
  • 2002 CHEVROLET TRAILBLAZER
Computer problem
2002 Chevy Trailblazer All Wheel Drive Automatic 179800 miles

where are the oxygen sensor located on this vehicle
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Tuesday, January 15th, 2019 AT 5:41 PM (Merged)
Tiny
MMPRINCE4000
  • EXPERT
O2 sensors are in the exhaust system. They screw into a "bung" welded to the exhaust.

There is usually an upstream (located before convertor) and downstream (located after convertor).

You will generally have to raise the vehicle, put on stands, and RR from under vehicle.
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Tuesday, January 15th, 2019 AT 5:41 PM (Merged)
Tiny
JOHN BEESLEY
  • MEMBER
  • 2003 CHEVROLET TRAILBLAZER
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 125,000 MILES
Where is the 02 Oxygen Sensor located and can this be replaced from the ground vs. Elevated

Thanks
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Tuesday, January 15th, 2019 AT 5:41 PM (Merged)
Tiny
DENNYP
  • EXPERT
It is located on the exhaust manifold. Change it from under the hood.
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Tuesday, January 15th, 2019 AT 5:41 PM (Merged)
Tiny
CHEVY MIKE
  • MEMBER
Look on the left side(facing under the hood). There is a heat sheild with approx eight nuts, Try the bottom nut on the sheild first, (8mm or 10mm)If it breaks, stop and bend the sheild out, and try an open end 22mm wrench via wheel well access, insert the wrench behind the sheild. If you can not get it loose you will have to cut the orginal oxy sensor and even break the end of the sensor off to get a socket on it. Make sure you have the correct one on hand.
Install the new one and use the open end wrench behind the heat sheild to tighten.
Autozone has it cheaper then oem. Bosch part #15285.

There is a before converter and after converter sensor, this is for the before sensor, never changed the after.
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Tuesday, January 15th, 2019 AT 5:41 PM (Merged)
Tiny
RANDYMI
  • MEMBER
  • 2006 CHEVROLET TRAILBLAZER
  • 85,000 MILES
I have a 2006 Trailblazer with a bad O2 Sensor. I am looking for advice on how to get the old sensor removed. It is the sensor on the exhaust manifold. I have borrowed a set of O2 sockets from Autozone, but I am only rounding off the edges of the sensor. I have tried warming up the engine and heating the area with a propane torch, and spraying a lot of PB blaster on it, but I still can't get it loose. I tried removing the heat shield, but those nuts are really rusted on, and I expect I will snap the bolts if I try to remove them. I would appreciate any tips.
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Tuesday, January 15th, 2019 AT 5:41 PM (Merged)

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