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Toyota Avalon Upstream O2 Sensor Kit
The upstream O2 sensor (often called the front sensor) is located before the catalytic converter. It measures the oxygen content in the exhaust gas and sends this data to the engine's computer. The computer then uses this information to make real-time adjustments to the air-fuel mixture, ensuring a clean and efficient burn. The downstream O2 sensor (or rear sensor) is located after the catalytic converter and monitors the oxygen levels to ensure the converter is working effectively to reduce harmful emissions. When either of these sensors fails, it can trigger the Check Engine light, leading to a noticeable decrease in fuel economy, a rough idle, or a failed emissions test. This product includes both sensors, allowing for a comprehensive and simultaneous replacement to restore your vehicle's emissions and fuel management systems to proper working order.
