---
product_id: 2441801
title: "234-9021 Upstream Heated Oxygen Sensor with 4-Wire Plug and 14.17â€ Harness"
brand: "denso"
price: "€ 268.59"
currency: EUR
in_stock: true
reviews_count: 4
url: https://www.desertcart.es/products/2441801-234-9021-upstream-heated-oxygen-sensor-with-4-wire-plug
store_origin: ES
region: Spain
---

# 4-wire electronic output 1500°F max temp rating 14.17-inch harness for easy install 234-9021 Upstream Heated Oxygen Sensor with 4-Wire Plug and 14.17â€ Harness

**Brand:** denso
**Price:** € 268.59
**Availability:** ✅ In Stock

## Summary

> 🔥 Stay ahead of the curve with precision that fuels performance!

## Quick Answers

- **What is this?** 234-9021 Upstream Heated Oxygen Sensor with 4-Wire Plug and 14.17â€ Harness by denso
- **How much does it cost?** € 268.59 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.es](https://www.desertcart.es/products/2441801-234-9021-upstream-heated-oxygen-sensor-with-4-wire-plug)

## Best For

- denso enthusiasts

## Why This Product

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

## Key Features

- • **OEM-Grade Quality:** Denso’s trusted engineering guarantees compatibility and reliability
- • **Lightweight & Durable:** Machined exterior with only 0.26 lbs for seamless integration
- • **Plug-and-Play Installation:** 14.17-inch harness and threaded mount make upgrades hassle-free
- • **Built to Endure Extreme Heat:** Operates reliably up to 1500°F for long-lasting performance
- • **Precision Air-Fuel Monitoring:** Zirconia solid electrolyte ensures ultra-accurate exhaust readings

## Overview

The Denso 234-9021 Upstream Heated Oxygen Sensor features a zirconia solid electrolyte for highly accurate air-fuel ratio detection. Designed with a durable machined exterior and a 4-wire electronic output, it withstands extreme temperatures up to 1500°F. Its 14.17-inch harness and threaded mounting ensure easy installation, making it an OEM-quality upgrade for optimal engine efficiency.

## Description

Denso 234-9021 Upstream Heated Oxygen Sensor with 4-Wire Plug and 14.17â€ Harness

## Features

- Manufactured to detect the amount of exhaust gas air fuel ratio
- Constructed from durable material
- Features zirconia solid electrolyte
- Highly accurate
- Easy installation

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Brand | DENSO |
| Material | Zirconia |
| Item Weight | 0.26 Pounds |
| Measurement Accuracy | High |
| Measuring Range | 0-20 AFR |
| Mounting Type | Threaded |
| Output Type | Electronic |
| Specific Uses For Product | Oxygen Sensor |
| Upper Temperature Rating | 1.5E+3 Degrees Fahrenheit |
| UPC | 042511110618 |
| Global Trade Identification Number | 00042511110618 |
| Manufacturer | Denso |
| Style | Modern |
| Model | Oxygen Sensor |
| Item Weight | 4.2 ounces |
| Item model number | 234-9021 |
| Is Discontinued By Manufacturer | No |
| Exterior | Machined |
| Manufacturer Part Number | 234-9021 |
| OEM Part Number | 234-9021 |

## Product Details

- **Brand:** DENSO
- **Material:** Zirconia
- **Item Weight:** 0.26 Pounds
- **Measurement Accuracy:** High
- **Measuring Range:** 0-20 AFR

## Images

![234-9021 Upstream Heated Oxygen Sensor with 4-Wire Plug and 14.17â€ Harness - Image 1](https://m.media-amazon.com/images/I/41vvMIJTTrL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Typical Great Denso Quality Part for My 2000 Avalon.
*by M***L on January 28, 2022*

First off, technically, this is a Air/Fuel sensor, NOT a O2 sensor. If you do your research you'll know they are not the same as some may say. They work differently and are not interchangeable. They even look different. Air/fuel sensors have less holes in the sensor end compared to O2 sensors. They are made differently with A/F having more rare earth material--hence quite a bit more expensive too. Always, Always go with factory OEM parts on A/F sensors because different car brands have specific voltage or current requirements for your vehicle and will not cure a sensor problem if not in the correct operating range. You'll be sorry if you don't go OEM. I replaced 2 of these A/F sensors on my V-6 3.0l--one each on each exhaust manifold, and a O2 sensor aft of the catalytic converter. Runs great! Fuel trims are spot on. Original Denso sensors lasted 180,000. I bought the car from a friend who had never had to change them. So Denso was my choice for replacement!

### ⭐⭐⭐⭐⭐ No issues with this sensor so far
*by E***R on April 1, 2011*

Product was well packaged and arrived ontime. I like the fact that Amazon forces you to verify if part is the right fit for the vehicle is a nice feature., so you won't order wrong part.I bought this product to fix the issue causing P1135 on my 2001 Sienna. I read the code and found out that Bank1 sensor 1 is bad (underneath steering column and hard to get to). I had a mechanic put in this part for me. No issues fitting the product in.I took the vehicle for emissions too soon after the installation. For the vehcicle to be testable, it needs have all monitors set to READY status. I had two of them not ready since the mechanic erased them all. Hence the vehicle was rejected. I waited for few more days before taking it again for emissions and it passed this time. FOR INFO: Note that I still have one of the systems monitor status set to "not ready". For 2001 model years onwards, you can have 1 system not ready and still pass the emissions if no other DTC or MIL exists. For 2000 and below years, 2 monitors can be not ready and still pass the test. (this is in IL)Overall with some googling and having some idea about vehicles, it saved me some $$$ to do dianose, buy the part and have it fixed myself. If I had to take it a mechanic for full service, the quotation I was given was $260+tax+Labor.

### ⭐⭐⭐⭐⭐ Exact Replacement, Solved the P1135 Error Code in 2002 Avalon XLS
*by R***Y on January 24, 2015*

I have a 2002 Toyota Avalon XLS. This was the exact replacement and it solved the P1135 code issue. My engine check and VSC lights came on. It was not caused from a bad or loose gas cap (which can also be the cause), so I went to Auto Zone and they checked the code for free with a code reader.The error code was P1135 for Bank 1 Sensor 1 Air Fuel Ratio Sensor. Of course, this is the most difficult sensor to reach (arrg!). It is in the exhaust manifold on the back side of the engine just in front of the firewall. You can only really reach it with one arm by coming in from the top of the engine on the driver's side down by the firewall. I could not reach it from under the car, there was no space for my arm to go in and do anything. You can see it from underneath, but that's about all.I ordered this part after verifying it was the correct one, along with the 02 sensor socket recommended (you really need to buy this!). I already had the PB spray. The hardest part was gaining access to get good leverage on the sensor with the wrench. I sprayed the old sensor with the PB spray a few times during the week letting it soak in. Once I got some leverage on the socket with the ratchet, the old sensor broke free. You have to get your body on top of the engine and use your body weight to push down on the ratchet with your arm. Once it broke loose I could then remove the old sensor with my fingers. Then next challenge was to unplug the electrical connector using only one hand. I sprayed WD40 on the connector which helped it come apart easier. FYI - you SQUEEZE the tab on the connector to unlock it.Once the old sensor was out, I sprayed the manifold hole with WD40, cleaned the threads with a toothbrush, then wiped the hole and area clean with a rag (you do most of this by feel only). The new Denso sensor comes with a small tube of anti-seize. It's more than enough, you could do 4 more with this. Put the anti-seize on the threads being careful not to get any on the sensor body.Replacement took only about 5 minutes, the new sensor screwed in perfectly to hand-tight then using the 02 socket it was easy to tighten fully. The connection of the new electrical cable is easy to do with one hand once you have the old one off because it simply clicks right together. Again, you have to do it by feel only.This saved me over $300 from going to the dealer and about $250 from having an aftermarket shop doing it. Patience and using lots of penetrating oil is the key!!!

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*Product available on Desertcart Spain*
*Store origin: ES*
*Last updated: 2026-03-01*