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Upstream Air Fuel Ratio Sensor

Name: Upstream Air Fuel Ratio Sensor for Toyota Tacoma Tundra 4Runner 3.4L V6 (2000-2004) | 234-9003
SKU: 234-9003 /J
Price: 49.95 USD
Availability: InStock

Fits Toyota Tacoma Tundra 4Runner 3.4L V6 (2000-2004)

Replaces OE: 234-9003

Resolves Symptoms:

Persistent Check Engine Light
Rough Idle
Poor Fuel Economy
Lean Hesitation

Delivery Free

Arrives: Sep 20 - Sep 23

Dispatched quickly from local US warehouses.

2-Year Warranty

🛡️ Quality Coverage: Protects against any manufacturing defects for 2 full years.

🔄 Free Replacement: Brand-new replacement for free if quality issues occur.

30-Day Return & Refund

📦 Free Returns: Zero costs to you if the product has quality issues.

💰 Full Refunds: 100% money-back guarantee within 30 days for defective items.

5-Step Fitment Guide

Check OE: Find original part no. & plug.
Compare Photos: Match plug with our images.
Verify YMM: Confirm via fitment tool.
Review Specs: Check pins & dimensions.
Purchase: Buy confidently once matched!

Review Rewards

Share an install photo & review to unlock:

Under $50 Orders: 3% Off Next Order
$50+ Orders: 5% Direct Cashback

*Email a screenshot of your review to support to claim.

Check if your car is compatible This helps guarantee fitment of parts.

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$49.95

No hidden fees: What you see is what you pay.
Restore performance: Fix issues and drive with confidence.

Check Engine Light? Find Your Symptoms

🌬️ O2 & A/F Sensors

P0134No Activity Detected
P0135Heater Circuit Malfunction
P0137/38Circuit Low/High Voltage
P2195Signal Stuck Lean
P0030/31Heater Control Circuit

⛽ Fuel & Air Mixture

P0171/74System Too Lean
P0172System Too Rich
P2096Post-Catalyst Trim Too Lean
P0087Fuel Rail Pressure Low
P0201-04Injector Circuit Open

♻️ Catalytic Converters

P0420Efficiency Below Threshold (B1)
P0430Efficiency Below Threshold (B2)

⚡ Ignition / Misfires

P0300Random Misfire
P0301-06Cylinder-Specific Misfire

Automotive-Leader Sensors

Applications

Year	Make	Model	Engine/Displacement	Note
2004	Toyota	Tacoma Base Crew Cab	3.4L V6	Pickup 4-Door, 3378CC, GAS, DOHC, Naturally Aspirated
2000-2004	Toyota	Tacoma Base Extended Cab	3.4L V6	Pickup 2-Door, 3378CC, GAS, DOHC, Naturally Aspirated
2000-2004	Toyota	Tacoma Base Standard Cab	3.4L V6	Pickup 2-Door, 3378CC, GAS, DOHC, Naturally Aspirated
2001-2004	Toyota	Tacoma Pre Runner Crew Cab	3.4L V6	Pickup 4-Door, 3378CC, GAS, DOHC, Naturally Aspirated
2000-2004	Toyota	Tacoma Pre Runner Extended Cab	3.4L V6	Pickup 2-Door, 3378CC, GAS, DOHC, Naturally Aspirated
2000-2004	Toyota	Tacoma Pre Runner Standard Cab	3.4L V6	Pickup 2-Door, 3378CC, GAS, DOHC, Naturally Aspirated
2000-2004	Toyota	Tacoma S-Runner Extended Cab	3.4L V6	Pickup 2-Door, 3378CC, GAS, DOHC, Naturally Aspirated
2000-2003	Toyota	Tacoma DLX Extended Cab	3.4L V6	Pickup 2-Door, 3378CC, GAS, DOHC, Naturally Aspirated
2000-2003	Toyota	Tacoma DLX Standard Cab	3.4L V6	Pickup 2-Door, 3378CC, GAS, DOHC, Naturally Aspirated
2000-2004	Toyota	Tundra Base Standard Cab	3.4L V6	Pickup 2-Door, 3378CC, GAS, DOHC, Naturally Aspirated
2004	Toyota	Tundra SR5 Crew Cab	3.4L V6	Pickup 4-Door, 3378CC, GAS, DOHC, Naturally Aspirated
2000-2004	Toyota	Tundra SR5 Extended Cab	3.4L V6	Pickup 4-Door, 3378CC, GAS, DOHC, Naturally Aspirated
2000-2004	Toyota	Tundra SR5 Standard Cab	3.4L V6	Pickup 2-Door, 3378CC, GAS, DOHC, Naturally Aspirated

Product Specifications

Warranty & Support: 2 Years + Pre-sale Quality Assurance + 24/7 Technical Support

Item	Specification
Core Part Number	89467-34010 Interchange: 89467-35020, 2132858, 5S4078, SU5645, ES10945
Position	Exhaust System, Front (Before Catalytic Converter)
Key Parameters	- Type: Heated Oxygen Sensor (Air Fuel Ratio Sensor) - Wire Configuration: 4-Wire - Product Fit: Direct Fit / Plug & Play - Performance: Fast response speed, stable output, close to effect - Construction: Excellent processing with high-temperature and corrosion-resistant materials for extended lifespan

Packaging：1Pcs 234-9003 Oxygen Sensor

FAQ & Support

🚦 1. Trouble Codes & Symptoms

Q1: My car shows codes like P0420 / P0171 / P0138. What do they mean?

These are common codes related to the fuel system or oxygen sensors:

P0420: Catalyst efficiency below threshold
P0171: System too lean
P0138: O2 sensor voltage high

They often indicate a worn oxygen sensor, exhaust leak, or ignition issue. If you're not sure, simply tell us your year, make, model, and engine—we'll check the exact part you need.

Q2: My engine shakes at idle. Is my ignition coil bad?

It's very possible. Common symptoms of a failing ignition coil include:

Rough idle or shaking
Hard cold starts
Poor acceleration
Higher fuel consumption
Misfire popping noise

Tell us your vehicle info—our team can help you identify the cause.

Q3: What are the symptoms of a bad oxygen sensor?

Typical signs include: Check Engine Light on, Increased fuel consumption, Poor acceleration, Strong fuel smell, and Slow throttle response.

Most sensors should be replaced every 80,000–100,000 km.

🔍 2. Fitment & Compatibility

Q4: How do I know which oxygen sensor fits my car?

Just provide: Year, Make, Model, and Engine size.

We'll confirm: Upstream or downstream, Correct connector, Proper reference number, and Federal vs. California emissions compatibility.

Q5: What's the difference between ignition coils?

High-quality aftermarket: Close to Standard but more affordable.

We only offer high-grade, reliable ignition coils.

Q6: How many oxygen sensors does my car have?

Most vehicles have 2–4 sensors (Upstream front and Downstream rear). We can confirm the exact number for your vehicle.

🛒 3. Buying, Quality & Concerns

Q7: Are cheap oxygen sensors reliable?

They work for a short time but usually cause issues like short lifespan, slow response, and frequent check engine lights.

We only sell new, high-quality, fully tested sensors.

Q8: How can I avoid buying a refurbished or used auto part?

Check for scratches on the connector, dirty wiring, or marks on threads.

Our parts are 100% brand new, never refurbished, and fully tested.

🧰 4. Installation & Usage

Q9: Can I install an oxygen sensor myself?

Yes. Difficulty: medium.

You'll need an O2 sensor socket, Anti-seize compound, and a Torque wrench. We recommend clearing fault codes with an OBD scanner after installation.

Q10: Do ignition coils need programming after replacement?

In most vehicles, no programming is required. Just swap the old coil with the new one.

💰 5. Value & Performance

Q11: Your parts cost less than Other accessories. Are they really reliable?

Yes—our parts use the same-grade materials and testing standards as suppliers. Because we don't go through dealer channels, the price is much more affordable.

About us

Since its inception, Automotive Leader has been guided by a simple mission: to provide high-performance aftermarket parts for automotive technicians and DIY enthusiasts.

The website is jointly operated by Trademark Name: Automotive-leader Store registered at Physical Address: Room 602, No. 152 Helong East Road, Helong Subdistrict, Baiyun District, Guangzhou City Postal Code: 510000 and Company name：BLUE STAR TRADING LIMITED registered at Company address：RM C，6/F，WORLD TRUST TOWER 50 STANLEY STREET CENTRAL HK

U.S. Address:
7600 LTC Parkway 34986
PORT SAINT LUCIE, FL - United States

whatsAPP Number: +86 18316212443

Email: support@automotive-leaderstore.com

Logistics Policy

1. U.S. Warehouse (Standard Option)
Handling time: 1-3 business days
Transit time (days): 3-6 business days via USPS/UPS/FedEx.

2. China Warehouse (Standard Option)
Handling time: 1-3 business days
Transit time (days): 14-22 business days via USPS/UPS/FedEx.

Refund and Return Policy

30-Day Returns and Refunds / Return shipping is free（Due to a product issue）

We do not accept direct exchanges.

After receiving and inspecting your returned item, we will notify you whether your refund has been approved.

If approved, the refund will be processed back to your original payment method within 5 business days.

Please note that your bank or credit card company may also require additional time to process and reflect the refund.

If you have not received your refund within 10 business days after your return request has been approved, please contact us.

Contact: support@automotive-leaderstore.com

Account

Upstream Air Fuel Ratio Sensor

🛠️ 1. Tools & Prep

📍 2. Locate & Remove

⚙️ 3. Install New

💻 4. Clear Codes

⚠️ 1. Relieve Pressure

⚙️ 2. Remove & Install

🔍 3. Check Leaks

📍 1. Locate & Remove

⚙️ 2. Install New

💻 3. Clear Codes

Automotive-Leader Sensors

Applications

Product Specifications

Customer Reviews

Subscribe to our email list to receive a VIP discount

FAQ & Support

🚦 1. Trouble Codes & Symptoms

🔍 2. Fitment & Compatibility

🛒 3. Buying, Quality & Concerns

🧰 4. Installation & Usage

💰 5. Value & Performance

About us

Logistics Policy

Refund and Return Policy

Country/Region

Country/Region

Upstream Air Fuel Ratio Sensor

🛠️ 1. Tools & Prep

📍 2. Locate & Remove

⚙️ 3. Install New

💻 4. Clear Codes

⚠️ 1. Relieve Pressure

⚙️ 2. Remove & Install

🔍 3. Check Leaks

📍 1. Locate & Remove

⚙️ 2. Install New

💻 3. Clear Codes

Automotive-Leader Sensors

Applications

Product Specifications

Customer Reviews

Subscribe to our email list to receive a VIP discount

FAQ & Support

🚦 1. Trouble Codes & Symptoms

🔍 2. Fitment & Compatibility

🛒 3. Buying, Quality & Concerns

🧰 4. Installation & Usage

💰 5. Value & Performance

About us

Logistics Policy

Refund and Return Policy