QIYBONE Oxygen O2 Sensor Pair for Toyota 2.5L L4 — Upstream & Downstream Replacement (2011–2018) OEM Fit, Stainless

QIYBONE oxygen sensors (upstream 250-54084 and downstream 250-24360) are a plug-and-play replacement pair engineered to restore accurate air-fuel readings on compatible Toyota, Lexus and Scion 2.5L L4 models.

These two sensors are built to meet OEM fit and function for select Toyota Camry, Avalon, RAV4, Scion tC and Lexus ES300h model years. Constructed from high-temperature stainless materials with reinforced sealing, the set provides a long-lasting electrical and physical connection so the engine control unit receives stable oxygen feedback for combustion management.

Which vehicles and years will these oxygen sensors fit?

These sensors are intended for 2.5L inline‑4 gasoline engines across specified model years. Verify OEM part numbers and connector shape against your factory sensor before ordering to ensure compatibility.

• Toyota Camry: 2012–2017 (2.5L L4)
• Toyota Avalon: 2013–2018 (2.5L L4)
• Toyota RAV4: 2013–2018 (2.5L L4) — excluding hybrid versions
• Scion tC: 2011–2016 (2.5L L4) and Lexus ES300h: 2013–2018 (2.5L L4)

How do these upstream and downstream sensors improve engine operation?

Upstream (pre-catalyst) and downstream (post-catalyst) sensors provide separate but complementary feedback to the vehicle ECU. The upstream sensor monitors immediate combustion mixture for fuel trim adjustments, while the downstream sensor tracks catalytic converter efficiency.

• Faster, more accurate oxygen readings help the ECU optimize air–fuel ratio
• Reduced risk of running rich or lean, improving fuel economy
• Downstream monitoring helps detect catalyst issues and emissions performance

What are the construction and durability features of these QIYBONE sensors?

QIYBONE designs these sensors with stainless steel housings and heat‑resistant internals to withstand under‑hood temperatures and road exposure. Improved sealing and shielding reduce the chance of moisture or contamination affecting signal reliability.

• Stainless steel body for corrosion resistance and strength
• High‑temperature materials inside for long service life
• Double protection sealing to minimize exposure to contaminants

How easy is installation and what should I check before replacing mine?

The sensors are made to OEM dimensions and use the factory‑style connector for a straightforward swap. Most installations take minutes if you have basic tools, though rusted fittings or difficult access points can add time.

• Compare connector shape and wire pinout to original sensor before purchase
• Sensor threads match OEM sizes for direct replacement (no modification)
• Use anti‑seize on threads if needed and tighten to manufacturer torque

Who is this for: Mechanics, DIY enthusiasts and fleet owners who need reliable replacement oxygen sensors for the listed Toyota, Lexus and Scion 2.5L models. Choose this QIYBONE upstream and downstream set if you want an OEM‑style, corrosion‑resistant pair that reinstates proper oxygen sensing and emissions feedback without custom wiring or adapters. Always confirm the part numbers and connector compatibility with your vehicle’s original sensors before installation to ensure a correct match.