O2 Sensor Delayed Response - Lean to Rich (Bank 1 Sensor 1)

The oxygen sensor on Bank 1 is responding too slowly when the engine transitions from running lean to running rich, preventing the engine computer from adjusting fuel mixture quickly enough. This sensor helps the engine maintain proper fuel balance, and a delayed response can cause rough running and poor fuel economy. The driver may notice hesitation, reduced performance, or increased emissions.

No detailed repair guide linked yet. Check back soon or search for related issues.