Woman Spends $680 on Repairs but Still Fails Emissions Test—Oxygen Sensor Replaced, System Still Not Ready

A Massachusetts-based esthetician recently shared her frustration on TikTok: after spending $680 to replace her car’s oxygen sensor and repair the exhaust system, her vehicle still failed its annual inspection. The inspection report indicated that the catalytic converter, evaporative emissions system, and oxygen sensor remained in a “not ready” state, preventing the emissions test from being completed. She said she had already driven 100 miles, yet the system still hadn’t reset. Many commenters suggested she drive an additional 160 to 250 miles to complete the onboard diagnostic (OBD) monitoring cycle, or look up the standard “drive cycle” procedure specific to her vehicle model. Others noted that the $680 repair cost seemed high, as oxygen sensor replacements typically range from $200 to $500. Experts warned that a faulty oxygen sensor can lead to excessive emissions and increased fuel consumption, advising drivers to thoroughly inspect their vehicles before undergoing annual inspections.