Ford OEM – (Front) O₂ Sensor – 2013-2018 Focus ST

Name: Ford OEM - (Front) O₂ Sensor – 2013-2018 Focus ST
SKU: 35045
Availability: InStock

$154.18

If you’re running a catless downpipe on your Focus ST, the upstream O2 sensor often needs replacing. Incorrect oxygen readings from the stock sensor can cause faulty AFR data, check engine lights, irregular RPMs, and backfire tune issues. This genuine Ford OEM upstream O2 sensor restores accurate pre-cat exhaust monitoring for reliable engine performance and smoother tuning.

Ford OEM - (Front) O₂ Sensor – 2013-2018 Focus ST

This item: Ford OEM - (Front) O₂ Sensor – 2013-2018 Focus ST

$154.18

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Categories: Focus ST Down Pipes, Focus ST Exhaust, Focus ST Sensors, Fittings, Misc. Components Tags: Ford OEM - (Front) O₂ Sensor – 2013-2018 Focus ST, Ford OEM front O2 sensor, o2 sensor, sesnor

Ford OEM – (Front) O₂ Sensor – 2013-2018 Focus ST

If you’re running a catless downpipe on your Focus ST, this is one of those parts that almost always needs replacing. The upstream O2 sensor monitors exhaust oxygen content before the catalytic converter and sends that data to the engine computer. Removing the cat can throw off those readings, which often leads to faulty AFR readings, erratic RPM behavior, backfire tune issues, and check engine lights.

This genuine Ford OEM upstream oxygen (O2) sensor is a direct replacement for the factory unit and restores correct exhaust measurement so your ECU can get accurate air-fuel ratio feedback. That means smoother tune response, less guesswork for your engine management, and a cleaner running ST whether you’re on stock or modified hardware.

Key Features

Direct OEM Fit: Exact fit for 2013–2018 Ford Focus ST 2.0 EcoBoost. Plug-and-play design with correct connector, wiring length, and sensor calibration.
Accurate Air/Fuel Feedback: Monitors pre-cat exhaust oxygen levels to keep your AFR data reliable — especially important after catless downpipe installs.
Prevents CEL & Tune Issues: Helps eliminate false check engine lights and erratic tuning behavior caused by incorrect upstream oxygen readings.
Built to Last: Genuine Ford part engineered for high temperature and exhaust environment durability.
Essential Service Part: Often replaced during performance upgrades or when AFR errors and lean/rich codes persist.

Application

Fits Ford Focus ST 2013-2018 2.0L EcoBoost vehicles as the upstream (primary) O2 sensor (before the catalytic converter).

Why EMS?:
We source this part directly from Ford OEM channels—no aftermarket knockoffs. You get factory specs, reliable performance, and total fitment confidence

Need help with installation?
If you’d like to schedule an O2 sensor install, give us a call at (423) 500-4901 or email sales@emsinc-tn.com and we’ll get you set up.