Replacement Oxygen Sensor for Toyota Tundra Tacoma 4Runner - Direct

In this review the focus is on a direct-replacement upstream oxygen sensor meant for early 2000s Toyota trucks and SUVs. The bottom line: this AA Ignition sensor is for DIY owners and independent shops who need a heated, four-wire upstream O2 sensor that matches factory fit and wiring to restore proper air/fuel feedback and clear the check engine light. It is most valuable when you confirm the plug and length match the old sensor before buying.

Key Features

• Replacement Upstream Sensor: Measures oxygen in exhaust and restores accurate air/fuel feedback so the engine and catalytic converter operate correctly.
• Vehicle Compatibility: Fits specified Toyota Tundra, Tacoma and 4Runner model years so buyers can find a direct swap for these early 2000s applications.
• Four-Wire Heated Design: The heated, four-wire construction delivers fast sensor warm-up and consistent readings for reliable closed-loop operation.
• OEM Fit and Finish: Made to match original part form and function so installation is straightforward and the sensor works like the factory unit.
• Replaces Multiple Part Numbers: Cross-references common OEM numbers so you can replace part# 234-9001 and related Toyota numbers with confidence.
• Lifetime Warranty: Includes a lifetime guarantee from the manufacturer, offering long-term protection against premature failure.

Who It's For

This sensor is best for owners of 2000-2004 Toyota Tundra 3.4L, 2001-2004 Toyota Tacoma 2.4L and 2.7L, and 2000 Toyota 4Runner 2.7L who want a cost-effective, direct-fit upstream oxygen sensor. It suits mechanically comfortable DIYers and independent repair shops that need a heated four-wire replacement that matches the original connector and wiring.

It is not for buyers who are unsure about connector type or sensor length; measuring the old sensor and checking pins is essential. Customers with different engine sizes, later model years, or downstream/secondary sensor needs should look for the exact sensor specified for those positions.

Pros & Cons

Pros

• Direct replacement design that restores proper O2 feedback and can clear CEL related to upstream sensor faults.
• Heated four-wire construction ensures quicker warm-up and stable readings in varied conditions.
• Covers multiple OEM part numbers, reducing the risk of buying the wrong replacement when matched correctly.
• Lifetime warranty provides added confidence for long-term use.

Cons

• Compatibility depends on plug style and sensor length, so buyers must verify the old sensor before ordering.
• Fit is specific to listed Toyota years and engines; it will not suit other positions or different model years.

Specifications

Our Verdict

The AA Ignition upstream oxygen sensor is a practical, value-minded replacement for owners of the specified early 2000s Toyota Tundra, Tacoma and 4Runner models who need a heated, four-wire direct swap. It restores proper O2 readings and can resolve related check engine light issues, provided buyers verify plug and length compatibility before purchase.

Frequently Asked Questions

Will this sensor fit my 2002 Tacoma?
If your 2002 Tacoma is the 2.4L or 2.7L and the original sensor is a front upstream heated four-wire with the same plug style and length, this sensor is a direct replacement.

Does the sensor include a warranty?
Yes, the sensor comes with a lifetime warranty from the manufacturer; contact them for replacement if it fails.

Can this replace a downstream sensor?
No, this listing is for the front upstream oxygen sensor; downstream or secondary positions may require a different part or connector.