Denso Oxygen/Air-Fuel Ratio Sensor 234-9005 for 2001–2005 Honda Civic, 2002–2004 CR-V/Acura RSX — OE-fit, Fast Response

Denso 234-9005 is a direct-replacement air/fuel ratio sensor engineered to restore accurate oxygen sensing and proper fuel trim for compatible 2001–2005 Honda and 2002–2004 Acura models.

When an oxygen or air/fuel ratio sensor begins to drift or fail it can cause rough idling, reduced fuel economy, and increased exhaust emissions. The Denso 234-9005 is built to the original-equipment standards to provide the correct electrical characteristics, mounting dimensions, and response speed for a first-time fit. This sensor is designed specifically for select Honda Civic, Honda CR-V, and Acura RSX model years, so replacement is straightforward and avoids the guesswork of cross-referencing incompatible parts.

Will this sensor fit my vehicle?

If your vehicle is listed for this part number, the Denso 234-9005 is a direct fit without modification. It covers Honda Civic model years 2001–2005, Honda CR-V 2002–2004, and Acura RSX 2002–2004. Always confirm the original part number or VIN compatibility before purchase to ensure exact fitment.

• Acura RSX: 2002–2004 direct replacement
• Honda Civic: 2001–2005 direct replacement
• Honda CR-V: 2002–2004 direct replacement
• Check OEM part numbers or vehicle VIN for confirmation

How does this air/fuel ratio sensor affect engine performance?

The air/fuel ratio sensor reports oxygen and fuel mixture information to the engine control unit (ECU), enabling precise fuel delivery and ignition timing adjustments. A correctly functioning sensor helps the ECU maintain efficient combustion across varying engine speeds and loads, which supports smoother operation and consistent throttle response.

• Improves fuel-trim accuracy across RPM range
• Supports stable idle and quicker response to throttle changes
• Helps maintain optimal catalytic converter function
• Reduces the risk of rich or lean running conditions

What are the build and quality features of the Denso 234-9005?

Denso manufactures its sensors to match OE specifications for electrical performance, housing dimensions, and connector type. The 234-9005 uses durable materials to withstand exhaust heat and contaminants, and Denso tests each unit for response time and output stability so you get a predictable replacement part.

• OE-standard electrical characteristics for compatibility
• Durable construction to resist exhaust exposure
• Tested for response speed and output reliability
• Engineered for first-time fit and straightforward installation

How easy is installation and what should I expect after replacement?

Installation is typically straightforward for anyone comfortable working under the vehicle; most technicians remove the old sensor, screw in the new sensor, and reconnect the wiring harness. After replacement, the ECU may require a short drive cycle to relearn fuel trims; you should notice restored fuel economy and fewer emission-related symptoms once learning completes.

• Threaded sensor design for standard installation tools
• Reconnects to factory wiring harness—no splicing required
• ECU relearn/driving cycle may be needed for optimal operation
• Expect improved fuel trims and reduced emissions signals

Who is this for: The Denso 234-9005 is intended for owners and repair shops servicing 2001–2005 Honda Civics, 2002–2004 Honda CR-Vs, and 2002–2004 Acura RSXs that need a reliable, OE-quality air/fuel ratio (oxygen) sensor. It’s a practical choice for DIY mechanics looking for a direct-fit replacement and for professionals who require a tested, consistent supplier part to restore proper engine management and emissions control.