Oxygen Sensor Socket Size: Which One to Buy
Most oxygen sensors take a 7/8 in (22mm) socket, with 27mm and 29mm sizes for other sensors, compared across four socket sets, chasers included.
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The oxygen sensor socket size most vehicles need is the standard size every set here includes, with larger sockets in some sets for thermal and oil pressure sensors, plus thread chasers for cleaning damaged threads. Match the socket to the sensor first, then to the drive size of the ratchet you own.
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Below: the sizes in these sets, how to match one to the sensor and the ratchet, and the gear itself.
DURATECH 5PCS O2 Oxygen Sensor Socket Set
A 5-piece O2 sensor socket set with 7/8 in (22mm) offset and long sockets in 3/8 in and 1/2 in drive, plus M12 and M18 thread chasers.
Pros
- Meets and exceeds ANSI/ASME standards
- Three 7/8 in (22mm) sockets: offset in both drives, plus a long socket
- Wide wire gate passes the sensor wire without damage
- Two thread chasers, M12 x 1.25mm and M18 x 1.5mm
Cons
- No warranty term stated
- Only the 22mm size; no 27mm socket for thermal or oil sensors
- Point count not stated
- No storage case stated
WORKPRO 7PCS O2 Oxygen Sensor Socket
A 7-piece O2 sensor socket set with 7/8 in (22mm) and 1-1/16 in (27mm) sockets in 3/8 in and 1/2 in drive, plus M12 and M18 thread chasers.
Pros
- Seven pieces, the widest socket range short of the 10-piece set
- Adds 27mm sockets for thermal and oil pressure sensors
- Wide wire gate and slotted square hole for anti-slip grip
- Two thread chasers, M12 x 1.25mm and M18 x 1.5mm
Cons
- Warranty field only says 'Provide Warranty Service', with no term
- No certification stated
- No weight or dimensions stated
- No case or storage stated
DNA MOTORING 10pcs Professional Oxygen Sensor
A 10-piece oxygen sensor socket set with 22mm, 27mm, 28mm, 29mm, 7/8 in and 1 in sizes in 3/8 in and 1/2 in drive, in forged chrome vanadium steel.
Pros
- Ten pieces, the widest size range here
- Forged hardened chrome vanadium steel, electroplated
- Cutout sides protect sensor wires and tubes
- Covers 22mm, 27mm, 28mm, 29mm, 7/8 in and 1 in sizes
Cons
- Spec table says 1 item while the title says 10 pieces
- One socket length is listed as 8mm where the others run 30mm to 110mm
- No warranty term; the listing says to contact the seller
- No thread chasers included
GIroiyai 5PCS Oxygen Sensor Wrench & Thread Repair
A 5-piece offset low-profile O2 sensor socket set in chrome vanadium steel, with 6-point sockets and two re-threading tools for standard 22mm sensors.
Pros
- Offset low-profile design for hard-to-reach sensors
- 6-point sockets for strong torque transfer without slipping
- Chrome vanadium steel resists deformation and wear
- Two re-threading tools for smooth sensor installation
Cons
- No drive sizes stated
- No thread chaser sizes stated
- No warranty term stated
- No weight stated
Oxygen sensor socket size: the sizes in these sets
Most oxygen sensors take a 7/8 in socket, given as 22mm, and all four sets include that size. Thermal sensor switches and oil pressure sensors take a 1-1/16 in socket, given as 27mm, and the WORKPRO and DNA sets include it. The DNA set adds 29mm, 28mm and 1 in sizes.
| Set | O2 socket | Other sizes | Thread chasers | Drive |
|---|---|---|---|---|
| DURATECH 5-Pc Set | 7/8 in (22mm) | None stated | M12 x 1.25mm, M18 x 1.5mm | 3/8 in and 1/2 in |
| WORKPRO 7-Pc Set | 7/8 in (22mm) | 1-1/16 in (27mm) thermal and oil | M12 x 1.25mm, M18 x 1.5mm | 3/8 in and 1/2 in |
| DNA MOTORING 10-Pc | 7/8 in (22mm) | 29mm, 28mm, 27mm, 1 in | None stated | 3/8 in and 1/2 in |
| GIroiyai 5-Pc Kit | 22mm | None stated | Two re-threading tools, sizes not stated | Not stated |
The 7/8 in size is the common thread across all four sets, which is why the answer to the size question starts there.
How to match the socket to the sensor and ratchet
Start with the sensor. Oxygen sensors and vacuum switches take the 22mm socket, while thermal sensor switches and oil pressure sensors take the 27mm socket. The DURATECH and WORKPRO sockets have a wide wire gate and the DNA sockets have cutout sides, so the sensor wire passes through without damage, and the offset sockets reach sensors tucked into tight spots.
Then match the drive. The DURATECH, WORKPRO and DNA sets work with 3/8 in and 1/2 in drive tools, and the DURATECH and WORKPRO thread chasers work with a 3/8 in ratchet. The GIroiyai listing states no drive size, so check it before ordering if the drive matters to you.
Then check the threads. The M12 x 1.25mm and M18 x 1.5mm thread chasers re-tap threads, clean and repair damaged threads, remove rust and prevent future cross-threading. The GIroiyai set includes two re-threading tools but states no sizes for them.
The gear: oxygen sensor socket size for the job
Each set below handles a different step of the same job: removing the sensor, reaching a tight one, or cleaning the threads it screws into.
Handling sensor sockets safely
Sensor work needs care around the wire and the threads. The wide wire gate on the DURATECH and WORKPRO sockets lets the sensor wire pass through without damage, and the slotted square hole holds the ratchet firmly with an anti-slip effect. The DNA set adds cutout sides to protect sensor wires and tubes, and an extended barrel design that shields surrounding components. Follow the vehicle manual.
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FAQ: garage tools
What size socket does an oxygen sensor take?
Most oxygen sensors take a 7/8 in socket, given as 22mm, and all four sets here include that size. It is the standard oxygen sensor size across the listings.
What is the 27mm socket for?
The 27mm socket, given as 1-1/16 in, is for thermal sensor switches and oil pressure sensors. The WORKPRO set includes a 27mm thermal sensor switch socket and a 27mm oil pressure sensor socket, and the DNA set includes a 27mm socket too.
What are thread chasers for?
Thread chasers re-tap threads, clean and repair damaged threads, remove rust and prevent future cross-threading. The DURATECH and WORKPRO sets include M12 x 1.25mm and M18 x 1.5mm chasers that work with a 3/8 in ratchet.
What drive size do O2 sensor sockets take?
The DURATECH, WORKPRO and DNA sets work with 3/8 in and 1/2 in drive tools. The DURATECH and WORKPRO thread chasers work with a 3/8 in ratchet. The GIroiyai listing states no drive size.
Do I need an offset socket?
It helps in tight spots. The DURATECH and WORKPRO sets include offset sockets, and the GIroiyai set is an offset low-profile set made for hard-to-reach sensors. A straight socket works where the sensor is out in the open.
Are these sockets covered by a warranty?
None of the four states a warranty term. The WORKPRO listing only says it provides warranty service, and the DNA listing says to contact the seller directly for warranty information.
Related: best oxygen sensor socket set, the best oxygen sensor socket set under 50, best penetrating oil for O2 sensor and spark plug socket sizes. Also see the best 3/8 torque wrench and the engine and shop equipment hub.
