O2 Oxygen Sensor Upstream Downstream for Toyota Tacoma (2000-2004) 2.7L, 3.4L

Direct-Fit Oxygen Sensor Pair for 2000-2004 Toyota Tacoma (N140/N150)

What it Does: The direct-fit oxygen sensor set replaces degraded factory upstream air-fuel ratio and downstream oxygen sensors on the 2000-2004 Tacoma to restore closed-loop fuel trim accuracy and eliminate catalytic efficiency diagnostic trouble codes.

The Stock Toyota Tacoma Sensor Degradation

Factory planar and thimble zirconia sensor elements on the first-generation N140/N150 Tacoma suffer from internal heater circuit failure, carbon fouling, and silica poisoning after prolonged thermal cycling. As the internal ceramic electrolyte ages, response time slows down significantly, forcing the engine control module into skewed open-loop or inaccurate closed-loop operating tables. This deterioration manifests as rich running conditions, degraded fuel economy, rough idle, and diagnostic fault codes such as P0130, P0133, P0135, or P0420.

The Engineering Solution

This upstream and downstream kit features heavy-duty 304 stainless steel sensor bodies, porous PTFE filters, and double-laser-welded housings that protect the sensing element from moisture and particulate contamination. Fast-light-off internal ceramic heaters reach optimal operating temperatures within seconds of engine startup, delivering rapid closed-loop transition and precise stoichiometric tracking. Each harness features OEM-grade wiring, high-temperature sleeving, and factory pin-out connectors to ensure plug-and-play installation without wire splicing or terminal modification.

What's Included

• 1x Upstream Oxygen / Air-Fuel Ratio Sensor
• 1x Downstream Oxygen Sensor

Technical Specifications

Compatibility

• 2000-2004 Toyota Tacoma 2.7L L4 (3RZ-FE)
• 2000-2004 Toyota Tacoma 3.4L V6 (5VZ-FE)

Frequently Asked Questions & Fitment Warnings

Does this fit the N140/N150 Tacoma?

Yes, this is a direct fit for the 2000-2004 Toyota Tacoma equipped with the 3RZ-FE 2.7L inline-four or 5VZ-FE 3.4L V6 engine. Confirm emissions specification (Federal vs. California emissions) before installation to ensure exact harness length and connector keying match your vehicle's exhaust layout.

Do these sensors require wire splicing or repinning?

No, these sensors feature factory-style direct-fit connectors and pre-terminated pigtails for true plug-and-play installation.

The Toyota Truck Caliber

Constructed to handle the heat, chassis vibration, and severe service demands of heavy hauling and off-road driving, these sensors maintain precise air-fuel monitoring under extreme load conditions.