---
product_id: 422788202
title: "Marsflex Air Fuel Ratio O2 Oxygen Sensor 234-9009 Upstream Compatible with Toyota Sienna Highlander Camry Avalon Lexus RX300 ES300, Replacement 250-54054"
brand: "marsflex"
price: "€ 49.55"
currency: EUR
in_stock: true
reviews_count: 8
url: https://www.desertcart.ie/products/422788202-marsflex-air-fuel-ratio-o2-oxygen-sensor-234-9009-upstream
store_origin: IE
region: Ireland
---

# High-temp ceramic core (-40℃~950℃) OE-spec easy installation Fast 20s response time Marsflex Air Fuel Ratio O2 Oxygen Sensor 234-9009 Upstream Compatible with Toyota Sienna Highlander Camry Avalon Lexus RX300 ES300, Replacement 250-54054

**Brand:** marsflex
**Price:** € 49.55
**Availability:** ✅ In Stock

## Summary

> 🚗 Upgrade your ride with precision sensing — because every drop of fuel counts!

## Quick Answers

- **What is this?** Marsflex Air Fuel Ratio O2 Oxygen Sensor 234-9009 Upstream Compatible with Toyota Sienna Highlander Camry Avalon Lexus RX300 ES300, Replacement 250-54054 by marsflex
- **How much does it cost?** € 49.55 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.ie](https://www.desertcart.ie/products/422788202-marsflex-air-fuel-ratio-o2-oxygen-sensor-234-9009-upstream)

## Best For

- marsflex enthusiasts

## Why This Product

- Trusted marsflex brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Plug & Play Fit:** Exact OE form and function ensures hassle-free installation in Toyota & Lexus models
- • **Trusted Warranty:** Backed by a 12-month warranty for peace of mind on every drive
- • **Long-Lasting Performance:** Tested for 10,000+ hours and 500 thermal cycles with 80,000-100,000 km lifespan
- • **Aerospace-Grade Durability:** Stainless steel housing & IP67 laser-sealed protection for extreme reliability
- • **Precision Fuel Optimization:** Restores ideal 14.7:1 air-fuel ratio for up to 15% better fuel economy

## Overview

The Marsflex Air Fuel Ratio O2 Oxygen Sensor 234-9009 is a high-precision upstream sensor compatible with select Toyota and Lexus models (1997-2003). Featuring aerospace-grade stainless steel housing, a high-temp ceramic core, and IP67 laser-sealed protection, it delivers fast 20-second response times and reliable data to optimize your engine’s air-fuel mixture. This sensor supports improved fuel economy by up to 15%, reduces emissions, and offers a robust lifespan of 80,000-100,000 km, all backed by a 12-month warranty.

## Description

Full description not available

## Features

- Cautions: Please check your vehicle fitment carefully in the product description to avoid any wrong purchase. Please check your part pictures with our pictures, especially the plug, it must be completely same. Or it will not fit your car
- Application: Marsflex Oxygen Sensor 234-9009 fit for Toyota 1997-1999 Avalon XLS/XL 1998 Camry CE 1998-2000 Camry LE/XLE 1999-2000 Sienna CE/LE/XLE 1999-2000 Solara SE/SLE 2001-2003 Highlander Limited/Base, Lexus 1998-1999 ES300 Base, 1999-2003 RX300 Base
- Durable and Reliable: Marsflex O2 sensors feature aerospace-grade stainless steel housing & high-temp ceramic core (-40℃~950℃ resistance). Laser-sealed IP67 protection withstands dust/water. Rigorously tested (10,000hrs + 500 thermal cycles) with anti-interference chip for precise signals. 80,000-100,000km lifespan, backed by12-month warranty. Proven durability worldwide!
- Easy Installation: Total length 15.7 inch. Manufactured to OE specification fit form and function, durable and easy installation
- Warranty: 1-YEAR WARRANTY. ALL Marsflex oxygen sensors are extensively tested during manufacturing to guarantee quality, reliability, and above all, always meet or exceed the original equipment specifications
- Improve Fuel Economy: Marsflex oxygen sensor helps optimize fuel efficiency by providing accurate real-time data to your engine’s ECU, ensuring the ideal air-fuel ratio (14.7:1). Over time, old sensors degrade, causing incorrect fuel mixtures (too rich or too lean). Replacing them with a high-precision Marsflex sensor restores proper combustion, potentially improving fuel economy by 5-15% while reducing emissions. For best performance, we recommend replacement every 60,000–80,000 km

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Brand | Marsflex |
| Item dimensions L x W x H | 5.91 x 2.17 x 2.17 inches |
| Material | 234-9009 |
| Item Weight | 0.13 Kilograms |
| Style | Upstream |
| Current Rating | 9 Amps |
| Lower Temperature Rating | 150 Degrees Celsius |
| Maximum Supply Voltage | 12 Volts |
| Measurement Accuracy | Go & No-go Gauge |
| Measuring Range | λ=0.6- ∞ |
| Mounting Type | Flange Mount |
| Output Type | Digital |
| Response Time | 20 seconds |
| Sensing Distance | 1000 Millimeters |
| Specific Uses For Product | Oxygen Sensor |
| Upper Temperature Rating | 930 Degrees Celsius |
| Manufacturer | Marsmotor |
| Item Weight | 4.6 ounces |
| Product Dimensions | 5.91 x 2.17 x 2.17 inches |
| Item model number | APEL14024 |
| Manufacturer Part Number | APEL14024 |
| Wattage | 20 watts |

## Product Details

- **Brand:** Marsflex
- **Item dimensions L x W x H:** 5.91 x 2.17 x 2.17 inches
- **Material:** 234-9009
- **Item Weight:** 0.13 Kilograms
- **Style:** Upstream

## Images

![Marsflex Air Fuel Ratio O2 Oxygen Sensor 234-9009 Upstream Compatible with Toyota Sienna Highlander Camry Avalon Lexus RX300 ES300, Replacement 250-54054 - Image 1](https://m.media-amazon.com/images/I/61ddlGyAFvL.jpg)
![Marsflex Air Fuel Ratio O2 Oxygen Sensor 234-9009 Upstream Compatible with Toyota Sienna Highlander Camry Avalon Lexus RX300 ES300, Replacement 250-54054 - Image 2](https://m.media-amazon.com/images/I/61g5O-Qv5qL.jpg)
![Marsflex Air Fuel Ratio O2 Oxygen Sensor 234-9009 Upstream Compatible with Toyota Sienna Highlander Camry Avalon Lexus RX300 ES300, Replacement 250-54054 - Image 3](https://m.media-amazon.com/images/I/61aDMb+u6ML.jpg)
![Marsflex Air Fuel Ratio O2 Oxygen Sensor 234-9009 Upstream Compatible with Toyota Sienna Highlander Camry Avalon Lexus RX300 ES300, Replacement 250-54054 - Image 4](https://m.media-amazon.com/images/I/6189n83wDZL.jpg)
![Marsflex Air Fuel Ratio O2 Oxygen Sensor 234-9009 Upstream Compatible with Toyota Sienna Highlander Camry Avalon Lexus RX300 ES300, Replacement 250-54054 - Image 5](https://m.media-amazon.com/images/I/614YZDcLRgL.jpg)

## Questions & Answers

**Q: What is the life expectancy of an oxygen sensor?**
A: Heated oxygen sensors should be checked or replaced every 60,000 miles, while unheated oxygen sensors should be checked or replaced every 30,000 miles

**Q: Do I need to replace all of the sensors at once?**
A: It is best to replace O2 sensors in pairs. Because, replacing one sensor will cause the ECU to set a code for the other sensors. This is because the new sensor switching activity is much faster than that of the older aged sensors

**Q: The oxygen sensor will not come out.**
A: If you are using an open end wrench, try an O2 socket. If this fails, try a long ratchet or breaker bar in conjunction with your socket to generate more torque. After the sensor is removed, be sure to use a thread cleaner to clean up the bung threads

**Q: Why does the fault code still exist after replacing the oxygen sensor?**
A: 1 Oxygen sensor circuit failure

**Q: Will this oxygen sensor work with my vehicle?**
A: Marsflex oxygen sensor is consistent with OEM, please refer to the page information for compatibility information. You can check 'Amazon confirmed it' for confirmation, or provide us with your vehicle information and we will confirm it for you.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Good fit and performance
*by W***T on February 17, 2025*

Perfect fot for my 01 Lexus rx300. I noticed an immediate difference, and I have zero complaints. Definitely recommended.

### ⭐⭐⭐⭐⭐ Exact replacement
*by T***Z on October 10, 2024*

My 2003 Toyota Highlander with 180,000 miles finally killed one of the O2 sensors and rather than spend $150+ for a name brand one, I figured this would work fine. Turned out to be the case. Side by side they almost look the same and the CEL turned off as soon as the sensor was replaced.Great value and functionality.

### ⭐ cheap alternative but does't work
*by M***D on November 29, 2023*

i was excited to find a cheaper alternative but the car start acting up 3 days after installing O2 sensors and lost power and after new diag turns to be the O2 sensors failed . replaced them with OEM (expensive ) but problem solved , now too late to return them .

## Frequently Bought Together

- Marsflex Air Fuel Ratio O2 Oxygen Sensor 234-9009 Upstream Compatible with Toyota Sienna Highlander Camry Avalon Lexus RX300 ES300, Replacement 250-54054
- Offset Oxygen Sensor Socket, 3/8-Inch Drive, 7/8-Inch (22mm), Wire Gate Accesses Sensor from Side, Preventing Damage to Wires, Universal for Most Cars
- Marsflex Oxygen O2 Sensor 234-4622 13355 Downstream Heated Compatible with Toyota Camry Avalon Sienna 4Runner RAV4 Solara Matrix Lexus ES300 Pontiac Vibe,250-24360 Replacement

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*Product available on Desertcart Ireland*
*Store origin: IE*
*Last updated: 2026-03-20*