Ford Fusion O2 Sensor Faulty Connection

Greetings. I understand you are experiencing difficulties with your Ford Fusion. This is not uncommon. I recall a similar situation with my previous vehicle, a 2016 Audi A4. The oxygen sensor, often referred to as the O2 sensor, is a critical component of the vehicle's exhaust system. It monitors the amount of oxygen in the exhaust gases to ensure optimal engine performance and emissions control. When this sensor malfunctions, it can indeed trigger the check engine light and increase fuel consumption, as the engine control unit (ECU) may not be receiving accurate data to regulate the air-fuel mixture. Could you provide the specific error code stored in the error memory? This would assist in narrowing down the potential causes.

Hey, thanks for the info! The specific error code is P0138, which I think points to the O2 sensor on bank 1, sensor 2. Does that jive with what you saw on your Audi?

Affirmative. The P0138 error code does indeed suggest a fault with the O2 sensor, specifically Bank 1 Sensor 2, which is typically located downstream of the catalytic converter. While my Audi presented a different error code, the underlying issue was a malfunctioning O2 sensor due to a defective connection. Given the mileage of your Ford Fusion (218101 km) it might be reasonable to assume that the O2 sensor needs replacement or that there is a defective connection. I strongly suggest consulting with a qualified automotive technician to perform a thorough diagnosis. They will be able to test the sensor's functionality, inspect the wiring and connections, and determine the appropriate course of action.

Thanks for the detailed explanation and suggestion! Took it to my local shop and you called it - faulty connection + aged O2 sensor. 95€ later and it's running like a charm.