Parts for your 2018 Subaru Exiga-Oxygen sensor

2018 Subaru Exiga oxygen sensor

Yes, the 2018 Subaru Exiga (sold in many markets as the Exiga Crossover 7) is fitted with oxygen sensors. Subaru’s own technical literature confirms this: the factory service manuals available through the Subaru Technical Information System (STIS) list both a front air–fuel ratio sensor (wideband oxygen sensor) and a rear oxygen sensor as part of the engine management and emissions systems on the FB25/EJ-series petrol engines used in late-model Exiga. The Subaru FAST parts catalogue for the Exiga likewise lists a “front A/F sensor” and a “rear O2 sensor” in the exhaust stream. This is consistent with OBD‑II/ADR requirements for petrol vehicles, which rely on upstream and downstream oxygen sensing to control fuelling and monitor the catalytic converter.

On a 2018 Exiga, the oxygen sensor’s job is to keep the engine running clean and efficient. The front air–fuel ratio sensor constantly samples exhaust gases just out of the manifold and tells the ECU whether the mix is rich or lean, letting the car trim fuelling on the fly. The rear oxygen sensor, mounted after the catalytic converter, keeps tabs on catalyst performance and helps trigger fault codes if emissions drift out of whack.

As part of routine servicing, it’s worth giving the oxygen sensor system a bit of attention—no need to replace it on a schedule unless Subaru specifies otherwise, but they do slowly age. By 120–160,000 km, a tired sensor can cause slightly worse fuel economy, a sooty tailpipe, hesitant throttle, or the check engine light. A scan with a proper OBD‑II tool will show live sensor data and any stored codes (common ones include mixture adaptation or catalyst efficiency).

• Keep connectors clean and wiring intact—heat and road grime can make a mess of them.
• Fix exhaust leaks before the sensors—false air will throw the readings right off.
• If replacement’s needed, use OEM-quality parts. Many A/F sensors are pre-coated, don’t add extra anti-seize or get grease on the tip.
• Only remove/install on a cool exhaust, use an O2-sensor socket, and tighten to the workshop manual torque spec.

With healthy sensors, the Exiga’s ECU can keep the mixture spot-on, helping it pass a WOF/rego emissions check, save a bit of petrol, and keep the catalytic converter happy for the long haul.

How many oxygen sensors does a 2018 Subaru Exiga have?

It typically has two: a front air–fuel ratio (wideband) sensor in the exhaust manifold and a rear oxygen sensor after the catalytic converter. The pair lets the ECU manage fuelling precisely and verify the catalyst is doing its job.

When should the oxygen sensors be replaced?

There’s usually no fixed interval, but many are due somewhere around 120–160,000 km or when symptoms show—poor economy, rough running, or a check engine light. Always confirm with scan data and fault codes before replacing.

Can it be driven with a faulty oxygen sensor?

Often yes, but it’s not ideal. The car may run rich, use more petrol, and risk catalyst damage. Best to diagnose promptly and sort it to avoid bigger bills down the track.