Parts for your 2015 Ford Territory-Oxygen sensor

2015 Ford Territory oxygen sensor — what it does and when to replace it

Technical sources confirm whether an oxygen sensor is relevant on a 2015 Ford Territory. The Ford SZ/SZ MkII Workshop Manual and Ford Australia’s Microcat parts catalogue list heated oxygen sensors (HO2S) fitted to the 4.0‑litre petrol Barra engine, both upstream and downstream of the catalytic converter, to meet ADR 79/03–79/04 emissions and OBD requirements. Bosch and NGK/NTK sensor catalogues also list direct-fit sensors for the SZ MkII petrol. By contrast, the 2.7‑litre TDCi diesel (AJD‑V6/Lion) as supplied to AU/NZ typically uses a diesel oxidation catalyst and exhaust gas temperature/pressure monitoring and is not shown with a lambda/oxygen sensor in the Ford WSM sensor map for that market.

For petrol-powered 2015 Territory models, the oxygen sensor is a small hero doing a big job. It constantly samples the oxygen content in the exhaust and tells the ECU how rich or lean the engine is running. That feedback keeps fuel trims tight, helps the cat do its thing, and saves a few bucks at the bowser. The Territory runs a sensor before the cat (upstream) to control mixture, and another after it (downstream) to monitor catalyst efficiency.

When these sensors age or get contaminated, the ECU can no longer fine‑tune properly. Common signs owners notice are higher fuel use, a lazier throttle, a rough idle, or a glowing check-engine light. Typical O2-related fault codes start with P013x or P015x. There’s no hard-and-fast replacement interval, but many see service life between about 120,000 and 200,000 km. If the Territory’s getting on in years or the fuel economy’s slipped, it’s worth testing and, if needed, swapping them as part of a big service.

• Best practice: use quality sensors (OE-equivalent from Bosch or NTK), replace in pairs if mileage is high, and inspect the wiring and connectors for heat damage.
• Fitting tips: allow the exhaust to cool, use a proper O2-sensor socket, and apply only sensor-safe anti-seize if the new unit doesn’t come pre-coated.
• Afterwards: clear codes, check for exhaust leaks, and complete a short drive cycle so trims relearn cleanly.

Got the diesel Territory? Don’t stress about an oxygen sensor you can’t find. That engine manages mixture and emissions with the MAF, MAP, EGR control, and exhaust temperature/pressure sensors. If chasing economy or smoke issues on the diesel, attention usually turns to the MAF, EGR system, boost leaks, or (where fitted) DPF differential-pressure and temp sensors rather than a lambda probe.

FAQs

Where are the oxygen sensors on a 2015 Ford Territory?
On the petrol model, one sits in the exhaust manifold or just after it (upstream) and another is mounted after the catalytic converter (downstream). The diesel variant in AU/NZ typically doesn’t have an oxygen sensor at all, so owners won’t find one in the exhaust.

How often should Territory oxygen sensors be replaced?
There’s no fixed schedule, but many fail or drift after 120,000–200,000 km. Replace when fault codes appear, fuel economy drops, or drivability suffers. As preventative maintenance on higher‑kilometre petrol cars, fresh upstream and downstream sensors can sharpen fuel trims and protect the cat.

Is it safe to drive with a faulty oxygen sensor?
Short-term, the ECU will run safer (richer) maps, but fuel use increases and the catalytic converter can cop a hiding if left too long. It’s fine to get home or to a workshop, but sort it promptly to avoid bigger bills.