Denso Air/Fuel Ratio Sensor 234-9049 Wide-Band 4-Wire Direct-Fit for Lexus/Scion/Toyota

Denso 234-9049 is a direct-fit wide-band air/fuel ratio sensor engineered to replace the original unit on select Lexus, Scion and Toyota vehicles.

This OEM-grade sensor measures the proportion of air to fuel entering the engine and communicates that data to the engine control unit so fuel delivery stays optimized. Manufactured and tested to Denso's strict specifications, the 234-9049 comes with a 4-wire harness (20.08 inches) and is built for a first-time fit in the listed model years. It’s designed to help maintain fuel efficiency, support stable combustion across RPMs, and protect emissions system components like the catalytic converter when installed correctly.

How will this sensor affect my vehicle’s fuel efficiency?

By providing precise, wide-band air/fuel readings, the sensor helps the engine computer adjust injector pulses to keep the mixture near the target ratio. That reduces wasted fuel from overly rich or lean conditions and can improve mileage consistency under varied driving loads.

• Wide-band sensing for accurate mixture data across RPM ranges
• Direct OE-style replacement minimizes tuning errors
• Consistent signal reduces corrective fuel trims that waste fuel

Will this fit my Lexus, Scion, or Toyota model?

Compatibility is specific to the model years listed for the Denso 234-9049; verify against your vehicle’s year and engine application before ordering. The product is intended as a like-for-like replacement for the vehicles noted, matching connector type and wiring length to avoid splicing.

• Fits select Lexus ES350, RX350 and RX450h model years
• Fits Scion tC and xB model years listed in the product details
• Fits various Toyota Avalon, Camry, Highlander, RAV4, Sienna and Solara years

What are the physical and electrical details I should know?

The sensor is a four-wire wide-band device with a 20.08-inch harness designed to match original equipment interfaces. Package dimensions and weight are compact, and the component is manufactured in the United States to Denso’s OE-quality standards.

• 4-wire wide-band design for precise ratio monitoring
• Wiring harness length: 20.08 inches for proper reach
• Compact packaging: 4.9 x 15.1 x 5.1 cm, weight ~0.128 kg

How does installing this sensor impact emissions system longevity?

Accurate air/fuel data keeps combustion balanced, which reduces unburned hydrocarbons and minimizes stress on the catalytic converter. While sensor replacement alone won’t cure all emissions issues, restoring precise mixture control helps the entire emissions system operate as intended.

• Helps maintain optimum combustion to lower harmful byproducts
• Reduces risk of catalyst-overload from prolonged rich running
• Provides stable signals that prevent long-term corrective fuel trims

Who is this for: Drivers and independent technicians who need a dependable OE-style replacement air/fuel ratio sensor for compatible Lexus, Scion and Toyota vehicles. It’s especially suited for owners aiming to restore factory fuel economy and emissions performance without aftermarket calibration. Confirm your vehicle’s year and engine compatibility before purchase to ensure a correct fit.