O2 Oxygen Sensor Upstream For Nissan Frontier Quest Sentra XterraReplace failing oxygen sensors on your Nissan with this direct fit 4 packengineered to eliminate check engine lights, restore fuel economy, and fix rough idle issues common on 1990s 2000s models. Fix the Most Common Check Engine Light Culprit If you're getting a check engine light on your 1990s or early 2000s Nissan, there's a strong chance it's related to oxygen sensors. Research shows faulty O2 sensors are among the most common causes of CEL codes