On the 6th-gen Explorer the upstream sensors are wideband air/fuel ratio sensors, not the old narrow-band type, and they sit right at the hottest part of the exhaust — in the turbo outlet on the EcoBoost engines and in the manifold on the 3.3L V6. That heat is the whole difficulty of the job: the threads bond to the exhaust casting, so soaking with penetrant well in advance and using a proper slotted 22 mm sensor socket instead of an open-end wrench is what separates a one-hour job from a snapped sensor and a downpipe removal.
The biggest mistake people make is buying a universal splice-in sensor. These engines run precise wideband feedback and generic sensors routinely throw fuel trim and heater circuit codes. The second mistake is guessing which bank is which — on the V6s, bank 1 is the passenger side, and the two sensors have different harness lengths, so ordering by VIN matters.
| Item | Type | |
|---|---|---|
| Floor jack 2-ton minimum, low profile Raise the Explorer to reach the downpipe/manifold sensors from below. | Required | shop |
| Jack stands 3-ton pair, used at the pinch weld/frame points Support the vehicle safely while you work under it. | Safety | shop |
| Wheel chocks Rubber pair Block the rear wheels since this platform is RWD-based and the front gets lifted. | Safety | shop |
| Socket set 8, 10, 13 mm, 1/4 and 3/8 in drive Removes the engine appearance cover studs, battery terminal, and underbody splash shield screws. | Required | shop |
| Torx bit socket set T25, T30, T40 Some belly pan and heat shield fasteners on 2020-2024 Explorers use Torx heads. | Required | shop |
| Trim/panel clip tool Plastic pry set Pops the push-pin retainers holding the front underbody shield and wheel liner. | Required | shop |
| Oxygen sensor socket 22 mm (7/8 in) slotted, 3/8 in drive The main tool — the slot clears the sensor harness while you unthread it. | Required | shop |
| Offset oxygen sensor wrench 22 mm (7/8 in) crow-foot style, 3/8 in drive Needed on the tight bank-2 sensor of the 3.0L and on the 3.3L manifolds where a straight socket will not fit. | Required | shop |
| Extension set 3/8 in drive, 3, 6 and 10 in, plus wobble/swivel adapter Reaches the sensor past the turbo heat shielding and subframe. | Required | shop |
| Breaker bar 3/8 or 1/2 in drive, 18 in Seized sensors on a turbo downpipe can take serious force to break loose. | Recommended | shop |
| Penetrating oil PB Blaster or equivalent Soak the sensor threads the night before to avoid stripping or snapping it. | Consumables | shop |
| Propane or MAP torch Hand torch Gently heating the boss expands it and frees a badly seized sensor — last resort only. | Recommended | shop |
| Wire brush Brass or stainless, small Cleans the threads in the exhaust boss before installing the new sensor. | Consumables | shop |
| Torque wrench 3/8 in drive, 10-80 ft-lb Sensor threads into an exhaust/turbo casting that is easy to overtighten. | Required | shop |
| Crow-foot torque adapter 22 mm, 3/8 in drive Lets you torque the sensor where a socket cannot be seated straight. | Recommended | shop |
| Nickel anti-seize High-temp, nickel-based (not copper) Only for the threads if the new sensor comes dry — never on the sensor tip or slots. | Consumables | shop |
| OBD2 scan tool Generic code reader, or FORScan with an OBDLink adapter Reads which sensor failed and clears the stored P013x/P015x codes afterward. | Recommended | shop |
| Upstream air/fuel ratio sensor Motorcraft DY- series specific to engine and bank (2.3L: one; 3.0L and 3.3L: bank 1 and bank 2 differ by lead length) The replacement sensor — order by VIN, connectors and pigtail lengths are not interchangeable. | Parts | shop |
| Mechanic's gloves Cut-resistant Exhaust and turbo shielding edges are sharp and hot. | Safety | shop |
| Safety glasses Rust and penetrating oil fall straight into your face on this job. | Safety | shop |
| Brake/electrical cleaner Non-chlorinated Cleans oil and grime off the boss area before you break the sensor loose. | Consumables | shop |
All engines in this generation use a 22 mm (7/8 in) oxygen sensor socket. The 2.3L EcoBoost has a single upstream sensor in the turbocharger outlet, reachable with a straight socket and extensions; the 3.0L EcoBoost has two, one per turbo, with bank 2 tight enough to require the offset crow-foot wrench. The 3.3L hybrid and Police 3.3L NA have two manifold-mounted sensors and need the offset wrench plus extra splash-shield removal, and the hybrid demands high-voltage precautions before going underneath.
| Upstream air/fuel ratio (HO2S) sensor | Approximately 35 ft-lb (48 Nm) — verify in the service manual for your engine |
| Underbody splash shield bolts/screws | verify in the service manual (hand-tight plus snug, typically under 8 ft-lb) |
| Wheel lug nuts (if a wheel is removed for access) | 111 ft-lb (150 Nm) |
| Battery negative terminal clamp | verify in the service manual (roughly 5-7 ft-lb) |
The 22 mm (7/8 in) sensor size and the 8/10/13 mm and T25-T40 access fasteners are standard across the 6th-gen Explorer range, but sensor location and pigtail length vary by engine and bank, so confirm the exact part by VIN and verify the final torque figure in the Ford workshop manual.
The 2.3L EcoBoost has two total: one upstream in the turbo outlet and one downstream after the catalyst. The 3.0L EcoBoost, 3.3L hybrid and 3.3L NA have four: two upstream (one per bank) and two downstream.
22 mm, which is the same as 7/8 in. Use a slotted oxygen sensor socket on 3/8 in drive so the harness passes through the slot, and keep a 22 mm offset crow-foot style wrench on hand for the tight bank-2 position on the V6s.
No programming is needed. Just clear the stored DTC with a scan tool and drive a mixed cycle so the PCM relearns fuel trims and the O2 monitors set to ready — important if you need an emissions test.
You can replace just the failed one. On a high-mileage V6 many people do both upstream sensors at the same time since the second one is usually close behind and you have already gone through the access work.