What is an oxygen sensor and how is it used in Chevrolet Avalanche,Silverado,Suburban,Tahoe,GMC Sierra,Yukon,Yukon Denali and Yukon XL's engine management system?

An oxygen sensor is a galvanic battery that produces a small voltage output in response to the amount of oxygen in the exhaust gases. This voltage signal is crucial for the feedback loop between the oxygen sensor and the Powertrain Control Module (PCM) to maintain the perfect air/fuel ratio of 14.7:1 that the catalyst needs for optimal operation. All vehicles covered have On-Board Diagnostics II (OBD-11) engine management systems, which means they have the ability to monitor the performance of the catalytic converter. All models covered by this manual have four heated oxygen sensors: one upstream sensor per cylinder bank and one downstream sensor per cylinder bank. Special care must be taken whenever a sensor is serviced, as they are extremely delicate and cannot be dropped or handled roughly. The upstream and downstream oxygen sensors are heated to speed up the warm-up time during which the sensors are unable to produce an accurate voltage signal. The circuit for each oxygen sensor heater is controlled by the PCM. To remove the upstream or downstream oxygen sensor, the vehicle must be raised and securely placed on jackstands. The sensor electrical lead must be traced to the connector and disconnected before unscrewing the sensor with an oxygen sensor socket. If the sensor is difficult to loosen, penetrating oil can be sprayed onto the sensor threads and allowed to soak in for a while. When installing the old sensor, anti-seize compound should be applied to the threads to facilitate future removal. If installing a new oxygen sensor, it's not necessary to apply anti-seize compound to the threads as they already have anti-seize compounds on them. The installation process is the reverse of removal, and the sensor must be tightened to the torque specifications.

Genuine Chevrolet Suburban Oxygen Sensor

Oxygen O2 Sensor

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29 Oxygen Sensors found

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Chevrolet Suburban Sensor,Heated Oxygen(Position 2)
Part Number: 12589321
$67.61 MSRP: $140.40
You Save: $72.79 (52%)
Ships in 1-3 Business Days
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Product Specifications
- Other Name: SENSOR, Computer Control Sensors; Front Oxygen Sensor, Oxygen Sensor
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2006-2007 Chevrolet Suburban | 1/2 TON, 3/4 TON | 8 Cyl 5.3L, 8 Cyl 5.3L Flex, 8 Cyl 6.0L
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Chevrolet Suburban Sensor,Heated Oxygen(Position 2)
Part Number: 12587785
$49.72 MSRP: $103.24
You Save: $53.52 (52%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: SENSOR, Computer Control Sensors; Oxygen Sensor
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2003-2005 Chevrolet Suburban | 1/2 TON, 1500 CREW CAB, 1500 CREW CAB LONG BOX, 1500 CREW CAB STANDARD BOX, 1500 EXTENDED CAB LONG BOX, 1500 EXTENDED CAB STANDARD BOX, 1500 REGULAR CAB LONG BOX, 1500 REGULAR CAB STANDARD BOX, 4 DOOR 1/2 TON, CLASSIC 1500 CREW CAB LONG BOX, CLASSIC 1500 EXTENDED CAB LONG BOX, CLASSIC 1500 EXTENDED CAB STANDARD BOX, CLASSIC 1500 REGULAR CAB LONG BOX, CLASSIC 1500 REGULAR CAB STANDARD BOX, EXT 1/2 TON, XL 1/2 TON, YUKON/DENALI | 8 Cyl 5.3L, 8 Cyl 5.3L Flex
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Chevrolet Suburban Sensor Asm,Heated Oxygen
Part Number: 19178918
$42.74 MSRP: $76.66
You Save: $33.92 (45%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: SENSOR, Computer Control Sensors; Oxygen Sensor
- Replaces: 25163079, 25312200
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 1996-1999 Chevrolet Suburban | 1/2 TON, 3/4 TON | 8 Cyl 5.7L
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Chevrolet Suburban Sensor Asm,Heated Oxygen (Position 2)
Part Number: 19178961
$55.14 MSRP: $114.49
You Save: $59.35 (52%)
Ships in 1 Business Day
ADD TO CART
Product Specifications
- Other Name: SENSOR, Computer Control Sensors; Oxygen Sensor
- Replaces: 25315809
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2000-2002 Chevrolet Suburban | 1/2 TON, 1500 CREW CAB LONG BOX, 1500 EXTENDED CAB LONG BOX, 1500 EXTENDED CAB STANDARD BOX, 1500 REGULAR CAB LONG BOX, 1500 REGULAR CAB STANDARD BOX, 4 DOOR 1/2 TON, CLASSIC 1500 CREW CAB LONG BOX, CLASSIC 1500 EXTENDED CAB LONG BOX, CLASSIC 1500 EXTENDED CAB STANDARD BOX, CLASSIC 1500 REGULAR CAB LONG BOX, CLASSIC 1500 REGULAR CAB STANDARD BOX, EXT 1/2 TON, XL 1/2 TON, YUKON/DENALI | 8 Cyl 5.3L
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Chevrolet Suburban Sensor Asm,Heated Oxygen (Position 2)
Part Number: 19178942
$85.40 MSRP: $155.28
You Save: $69.88 (45%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: SENSOR, Computer Control Sensors; Oxygen Sensor
- Replaces: 25315814
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2000 Chevrolet Suburban | 2500 EXTENDED CAB LONG BOX, 2500 EXTENDED CAB STANDARD BOX, 2500 REGULAR CAB, 3/4 TON, CLASSIC 2500 EXTENDED CAB LONG BOX, CLASSIC 2500 EXTENDED CAB STANDARD BOX, CLASSIC 2500 REGULAR CAB, XL 3/4 TON | 8 Cyl 6.0L
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Chevrolet Suburban Sensor Asm,Heated Oxygen
Part Number: 19178934
$67.29 MSRP: $139.72
You Save: $72.43 (52%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: SENSOR, Computer Control Sensors; Oxygen Sensor
- Replaces: 25160540, 25312191
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 1996-1999 Chevrolet Suburban | 1/2 TON, 3/4 TON | 8 Cyl 5.7L, 8 Cyl 7.4L
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Chevrolet Suburban Sensor Assembly, Heated Oxygen(Pre, Catalyst Bank 1 Se
Part Number: 12659516
$52.57 MSRP: $109.16
You Save: $56.59 (52%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: SENSOR, Computer Control Sensors
- Replaces: 12637679
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2015-2020 Chevrolet Suburban | 1500 4 DOOR UTILITY | 8 Cyl 5.3L, 8 Cyl 6.2L
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Chevrolet Suburban Sensor Assembly, Heated Oxygen (Pre, Catalyst Bank 2 S
Part Number: 12666673
$41.61 MSRP: $86.40
You Save: $44.79 (52%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: SENSOR, Computer Control Sensors; Front Oxygen Sensor, Oxygen Sensor
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2016-2020 Chevrolet Suburban | 1500 4 DOOR UTILITY | 8 Cyl 5.3L, 8 Cyl 6.2L
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Chevrolet Suburban Sensor Assembly, Heated Oxygen (Position 2)
Part Number: 12583804
$50.96 MSRP: $105.82
You Save: $54.86 (52%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: SENSOR, Computer Control Sensors; Front Oxygen Sensor, Oxygen Sensor
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2008-2014 Chevrolet Suburban | 1/2 TON, 3/4 TON | 8 Cyl 5.3L, 8 Cyl 5.3L Flex, 8 Cyl 6.0L, 8 Cyl 6.0L Flex
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Chevrolet Suburban Sensor Asm,Heated Oxygen (Position 3)
Part Number: 19209808
$49.59 MSRP: $102.98
You Save: $53.39 (52%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: SENSOR, Computer Control Sensors; Oxygen Sensor, Rear Oxygen Sensor
- Replaces: 25333812, 12573168, 12583806, 19210711, 12575389, 19256731
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2002-2006 Chevrolet Suburban | 1/2 TON, 1500 CREW CAB, 1500 CREW CAB LONG BOX, 1500 CREW CAB STANDARD BOX, 1500 EXTENDED CAB LONG BOX, 1500 EXTENDED CAB STANDARD BOX, 1500 REGULAR CAB LONG BOX, 1500 REGULAR CAB STANDARD BOX, 2500 CREW CAB LONG BOX, 2500 CREW CAB STANDARD BOX, 2500 EXTENDED CAB LONG BOX, 2500 EXTENDED CAB STANDARD BOX, 2500 REGULAR CAB, 3/4 TON, 3500 CHASSIS EXTENDED CAB 161.5, 3500 CHASSIS EXTENDED CAB 185.5, 3500 CHASSIS REGULAR CAB 137.0, 3500 CHASSIS REGULAR CAB 161.5, 3500 CREW CAB, 3500 EXTENDED CAB, 3500 REGULAR CAB, 4 DOOR 1/2 TON, CLASSIC 1500 CREW CAB LONG BOX, CLASSIC 1500 EXTENDED CAB LONG BOX, CLASSIC 1500 EXTENDED CAB STANDARD BOX, CLASSIC 1500 REGULAR CAB LONG BOX, CLASSIC 1500 REGULAR CAB STANDARD BOX, CLASSIC 2500 CREW CAB LONG BOX, CLASSIC 2500 CREW CAB STANDARD BOX, CLASSIC 2500 EXTENDED CAB LONG BOX, CLASSIC 2500 EXTENDED CAB STANDARD BOX, CLASSIC 2500 REGULAR CAB, CLASSIC 3500 CHASSIS EXTENDED CAB 161.5, CLASSIC 3500 CREW CAB, CLASSIC 3500 EXTENDED CAB, CLASSIC 3500 REGULAR CAB, EXT 1/2 TON, EXT 3/4 TON, XL 1/2 TON, XL 3/4 TON, YUKON/DENALI | 8 Cyl 6.0L
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Chevrolet Suburban Sensor,Heated Oxygen(Position 2)
Part Number: 12572705
$84.49 MSRP: $175.44
You Save: $90.95 (52%)
Ships in 1 Business Day
ADD TO CART
Product Specifications
- Other Name: SENSOR, Computer Control Sensors; Front Oxygen Sensor, Oxygen Sensor
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2003-2006 Chevrolet Suburban | 1/2 TON, 1500 CREW CAB, 1500 CREW CAB LONG BOX, 1500 CREW CAB STANDARD BOX, 1500 EXTENDED CAB LONG BOX, 1500 EXTENDED CAB STANDARD BOX, 1500 REGULAR CAB LONG BOX, 1500 REGULAR CAB STANDARD BOX, 2500 CREW CAB LONG BOX, 2500 CREW CAB STANDARD BOX, 2500 EXTENDED CAB LONG BOX, 2500 EXTENDED CAB STANDARD BOX, 2500 REGULAR CAB, 3/4 TON, 3500 CHASSIS EXTENDED CAB 161.5, 3500 CHASSIS REGULAR CAB 137.0, 3500 CHASSIS REGULAR CAB 161.5, 3500 CREW CAB, 3500 EXTENDED CAB, 3500 REGULAR CAB, 4 DOOR 1/2 TON, CLASSIC 1500 CREW CAB LONG BOX, CLASSIC 1500 EXTENDED CAB LONG BOX, CLASSIC 1500 EXTENDED CAB STANDARD BOX, CLASSIC 1500 REGULAR CAB LONG BOX, CLASSIC 1500 REGULAR CAB STANDARD BOX, CLASSIC 2500 CREW CAB LONG BOX, CLASSIC 2500 CREW CAB STANDARD BOX, CLASSIC 2500 EXTENDED CAB LONG BOX, CLASSIC 2500 EXTENDED CAB STANDARD BOX, CLASSIC 2500 REGULAR CAB, CLASSIC 3500 CHASSIS EXTENDED CAB 161.5, CLASSIC 3500 CREW CAB, CLASSIC 3500 EXTENDED CAB, CLASSIC 3500 REGULAR CAB, EXT 1/2 TON, EXT 3/4 TON, XL 1/2 TON, XL 3/4 TON, YUKON/DENALI | 8 Cyl 6.0L, 8 Cyl 8.1L
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Chevrolet Suburban Sensor,Heated Oxygen(Position 1)
Part Number: 12576131
$48.16 MSRP: $100.02
You Save: $51.86 (52%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: SENSOR, Computer Control Sensors; Front Oxygen Sensor, Oxygen Sensor
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2005 Chevrolet Suburban | 1/2 TON | 8 Cyl 5.3L, 8 Cyl 5.3L Flex
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Chevrolet Suburban Sensor,Heated Oxygen(Position 3)
Part Number: 12599866
$64.95 MSRP: $134.85
You Save: $69.90 (52%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: SENSOR, Computer Control Sensors; Oxygen Sensor
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2006 Chevrolet Suburban | 1/2 TON | 8 Cyl 5.3L, 8 Cyl 5.3L Flex
View related parts
Chevrolet Suburban Sensor Asm,Heated Oxygen (Position 3)
Part Number: 19209812
$69.25 MSRP: $143.78
You Save: $74.53 (52%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: SENSOR, Computer Control Sensors; Oxygen Sensor
- Replaces: 25333817, 19210423
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2002-2006 Chevrolet Suburban | 1500 CREW CAB LONG BOX, 2500 CREW CAB LONG BOX, 2500 CREW CAB STANDARD BOX, 2500 EXTENDED CAB LONG BOX, 2500 EXTENDED CAB STANDARD BOX, 2500 REGULAR CAB, 3/4 TON, 3500 CHASSIS EXTENDED CAB 161.5, 3500 CHASSIS EXTENDED CAB 185.5, 3500 CHASSIS REGULAR CAB 137.0, 3500 CHASSIS REGULAR CAB 161.5, 3500 CREW CAB, 3500 EXTENDED CAB, 3500 REGULAR CAB, CLASSIC 1500 CREW CAB LONG BOX, CLASSIC 2500 CREW CAB LONG BOX, CLASSIC 2500 CREW CAB STANDARD BOX, CLASSIC 2500 EXTENDED CAB LONG BOX, CLASSIC 2500 EXTENDED CAB STANDARD BOX, CLASSIC 2500 REGULAR CAB, CLASSIC 3500 CHASSIS EXTENDED CAB 161.5, CLASSIC 3500 CREW CAB, CLASSIC 3500 EXTENDED CAB, CLASSIC 3500 REGULAR CAB, EXT 3/4 TON, XL 3/4 TON | 8 Cyl 6.0L
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Chevrolet Suburban Sensor Assembly, Heated Oxygen
Part Number: 12565397
$63.26 MSRP: $131.37
You Save: $68.11 (52%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: SENSOR, Computer Control Sensors; Oxygen Sensor
- Replaces: 12563346
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2001-2002 Chevrolet Suburban | 1/2 TON, 1500 CREW CAB LONG BOX, 1500 EXTENDED CAB LONG BOX, 1500 EXTENDED CAB STANDARD BOX, 1500 REGULAR CAB LONG BOX, 1500 REGULAR CAB STANDARD BOX, 2500 CREW CAB LONG BOX, 2500 CREW CAB STANDARD BOX, 2500 EXTENDED CAB LONG BOX, 2500 EXTENDED CAB STANDARD BOX, 2500 REGULAR CAB, 3/4 TON, 3500 CHASSIS EXTENDED CAB 185.5, 3500 CREW CAB, 3500 EXTENDED CAB, 3500 REGULAR CAB, 4 DOOR 1/2 TON, CLASSIC 1500 CREW CAB LONG BOX, CLASSIC 1500 EXTENDED CAB LONG BOX, CLASSIC 1500 EXTENDED CAB STANDARD BOX, CLASSIC 1500 REGULAR CAB LONG BOX, CLASSIC 1500 REGULAR CAB STANDARD BOX, CLASSIC 2500 CREW CAB LONG BOX, CLASSIC 2500 CREW CAB STANDARD BOX, CLASSIC 2500 EXTENDED CAB LONG BOX, CLASSIC 2500 EXTENDED CAB STANDARD BOX, CLASSIC 2500 REGULAR CAB, CLASSIC 3500 CHASSIS EXTENDED CAB 161.5, CLASSIC 3500 CREW CAB, CLASSIC 3500 EXTENDED CAB, CLASSIC 3500 REGULAR CAB, EXT 1/2 TON, EXT 3/4 TON, XL 1/2 TON, XL 3/4 TON, YUKON/DENALI | 8 Cyl 6.0L, 8 Cyl 8.1L
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Chevrolet Suburban Sensor Assembly, Htd Oxy (Post, Catalyst Bank 1
Part Number: 12670253
$36.14 MSRP: $75.04
You Save: $38.90 (52%)
Ships in 1 Business Day
ADD TO CART
Product Specifications
- Other Name: Lower Oxygen Sensor, Oxygen Sensor
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2021 Chevrolet Suburban | 1/2 TON | 8 Cyl 5.3L, 8 Cyl 6.2L
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Chevrolet Suburban Sensor Assembly, Htd Oxy (Pre, Catalyst Bank 2 S
Part Number: 12687606
$35.55 MSRP: $73.82
You Save: $38.27 (52%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: Oxygen Sensor, Upper Oxygen Sensor
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2021 Chevrolet Suburban | 1/2 TON | 8 Cyl 5.3L, 8 Cyl 6.2L
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Chevrolet Suburban SENSOR ASM,HTD OXY<DO NOT USE, CONTACT TECH SPECIALIST
Part Number: 19355306
$55.10 MSRP: $114.42
You Save: $59.32 (52%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: Oxygen Sensor
- Replaces: 25163080, 25312201, 19178116
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 1996-2002 Chevrolet Suburban | 1/2 TON, 1500 CREW CAB LONG BOX, 1500 EXTENDED CAB LONG BOX, 1500 EXTENDED CAB STANDARD BOX, 1500 REGULAR CAB LONG BOX, 1500 REGULAR CAB STANDARD BOX, 2500 CREW CAB LONG BOX, 2500 CREW CAB STANDARD BOX, 2500 EXTENDED CAB LONG BOX, 2500 EXTENDED CAB STANDARD BOX, 2500 REGULAR CAB, 3/4 TON, 3500 CHASSIS EXTENDED CAB 185.5, 3500 CREW CAB, 3500 EXTENDED CAB, 3500 REGULAR CAB, 4 DOOR 1/2 TON, CLASSIC 1500 CREW CAB LONG BOX, CLASSIC 1500 EXTENDED CAB LONG BOX, CLASSIC 1500 EXTENDED CAB STANDARD BOX, CLASSIC 1500 REGULAR CAB LONG BOX, CLASSIC 1500 REGULAR CAB STANDARD BOX, CLASSIC 2500 CREW CAB LONG BOX, CLASSIC 2500 CREW CAB STANDARD BOX, CLASSIC 2500 EXTENDED CAB LONG BOX, CLASSIC 2500 EXTENDED CAB STANDARD BOX, CLASSIC 2500 REGULAR CAB, CLASSIC 3500 CHASSIS EXTENDED CAB 161.5, CLASSIC 3500 CREW CAB, CLASSIC 3500 EXTENDED CAB, CLASSIC 3500 REGULAR CAB, EXT 1/2 TON, XL 1/2 TON, XL 3/4 TON, YUKON/DENALI | 8 Cyl 5.3L, 8 Cyl 5.7L, 8 Cyl 6.0L, 8 Cyl 7.4L
View related parts
Chevrolet Suburban Sensor Asm,Heated Oxygen (Position 3)
Part Number: 19209815
$82.25 MSRP: $170.78
You Save: $88.53 (52%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: SENSOR, Computer Control Sensors; Oxygen Sensor, Rear Oxygen Sensor
- Replaces: 12590847
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2007 Chevrolet Suburban | 1/2 TON, 3/4 TON | 8 Cyl 5.3L, 8 Cyl 5.3L Flex, 8 Cyl 6.0L
View related parts
Chevrolet Suburban Sensor Assembly, Heated Oxygen
Part Number: 12565415
$53.13 MSRP: $170.94
You Save: $117.81 (69%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: SENSOR, Computer Control Sensors; Oxygen Sensor
- Warranty: This genuine part is guaranteed by GM's factory warranty.
Fits the following Vehicles:
- 2001-2002 Chevrolet Suburban | 2500 CREW CAB LONG BOX, 2500 CREW CAB STANDARD BOX, 2500 EXTENDED CAB LONG BOX, 2500 EXTENDED CAB STANDARD BOX, 2500 REGULAR CAB, 3/4 TON, 3500 CHASSIS EXTENDED CAB 185.5, 3500 CREW CAB, 3500 EXTENDED CAB, 3500 REGULAR CAB, CLASSIC 2500 CREW CAB LONG BOX, CLASSIC 2500 CREW CAB STANDARD BOX, CLASSIC 2500 EXTENDED CAB LONG BOX, CLASSIC 2500 EXTENDED CAB STANDARD BOX, CLASSIC 2500 REGULAR CAB, CLASSIC 3500 CHASSIS EXTENDED CAB 161.5, CLASSIC 3500 CREW CAB, CLASSIC 3500 EXTENDED CAB, CLASSIC 3500 REGULAR CAB, EXT 3/4 TON, XL 3/4 TON | 8 Cyl 8.1L

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Chevrolet Suburban Oxygen Sensor Parts Questions & Experts Answers

Sensor Assembly, Heated Oxygen (Position 3)
12609457
Q: What is an oxygen sensor and how is it used in Chevrolet Avalanche,Silverado,Suburban,Tahoe,GMC Sierra,Yukon,Yukon Denali and Yukon XL's engine management system?
A: An oxygen sensor is a galvanic battery that produces a small voltage output in response to the amount of oxygen in the exhaust gases. This voltage signal is crucial for the feedback loop between the oxygen sensor and the Powertrain Control Module (PCM) to maintain the perfect air/fuel ratio of 14.7:1 that the catalyst needs for optimal operation. All vehicles covered have On-Board Diagnostics II (OBD-11) engine management systems, which means they have the ability to monitor the performance of the Catalytic Converter. All models covered by this manual have four heated oxygen sensors: one upstream sensor per cylinder bank and one downstream sensor per cylinder bank. Special care must be taken whenever a sensor is serviced, as they are extremely delicate and cannot be dropped or handled roughly. The upstream and downstream oxygen sensors are heated to speed up the warm-up time during which the sensors are unable to produce an accurate voltage signal. The circuit for each oxygen sensor heater is controlled by the PCM. To remove the upstream or downstream oxygen sensor, the vehicle must be raised and securely placed on jackstands. The sensor electrical lead must be traced to the connector and disconnected before unscrewing the sensor with an oxygen sensor socket. If the sensor is difficult to loosen, penetrating oil can be sprayed onto the sensor threads and allowed to soak in for a while. When installing the old sensor, anti-seize compound should be applied to the threads to facilitate future removal. If installing a new oxygen sensor, it's not necessary to apply anti-seize compound to the threads as they already have anti-seize compounds on them. The installation process is the reverse of removal, and the sensor must be tightened to the torque specifications.