Parts for your 2013 Mitsubishi Lancer-Oxygen sensor

2013 Mitsubishi Lancer oxygen sensor — what it does and when to replace it

Based on Mitsubishi Motors workshop documentation for the CJ/CF Lancer platform (covering the 2013 model year), the vehicle is fitted with two oxygen-sensing devices: a front air–fuel ratio (wideband) sensor ahead of the catalytic converter and a rear heated oxygen (narrowband) sensor after the cat. This layout is also confirmed by OEM parts catalogues (Mitsubishi ASA) and major fitment guides from Denso and NGK/NTK, and aligns with ADR/EOBD emissions requirements for petrol Lancers of this era. So yes—the 2013 Mitsubishi Lancer uses oxygen sensors.

On a 2013 Lancer, the oxygen sensor setup is there to keep fuelling spot-on and emissions tidy. The front air–fuel ratio sensor constantly feeds the ECU with precise mixture data so it can trim fuel on the fly, helping the car run sweet as at cruise and under load. The rear oxygen sensor watches how well the catalytic converter is doing its job. Together they help with decent fuel economy, smoother drivability, and keeping that check-engine light off.

There’s no hard-and-fast replacement interval in the factory maintenance schedule because the ECU monitors sensor performance. Still, many owners consider inspection or proactive replacement somewhere around 160,000 km, especially if fuel economy is slipping or there are intermittent drivability niggles. Always scan for fault codes and check short- and long-term fuel trims before throwing parts at it—wideband sensors in particular need correct diagnosis.

Common signs an oxygen sensor is on the way out include:

• Higher fuel use, rough idle, or sluggish throttle response
• Check-engine light with mixture or catalyst codes (e.g., P013x, P0420)
• Failed emissions test or sulphur/“rotten egg” smells

When replacing, stick with quality OEM-equivalent parts (Denso, NGK/NTK) and the exact sensor type for the engine—4B11/4B12 non‑turbo and 4B11T turbo models use different calibrations and connectors. Avoid universal splice-in units on the wideband front sensor, a plug-and-play sensor saves headaches. Don’t contaminate the sensor tip with anti‑seize or silicone, most new sensors come with the correct thread coating. If the exhaust has leaks upstream of the sensor, fix those first or the readings will be off.

For turbo Ralliart/Evo variants, keep an eye on any post‑turbo flange leaks and ensure the car isn’t exposed to leaded fuels or sealants that can poison the sensor or the cat. A quick visual check of wiring, regular scans of fuel trims, and addressing misfires promptly will help the oxygen sensors and catalytic converter live a long, drama‑free life.

How many oxygen sensors does a 2013 Mitsubishi Lancer have?

Most 2013 Lancer petrol models run two: a front air–fuel ratio (wideband) sensor before the catalytic converter and a rear heated oxygen sensor after it. Ralliart and Evo variants also use a two‑sensor arrangement, though part numbers and calibration differ.

What are the signs the oxygen sensor needs replacing?

Tell‑tales include higher fuel consumption, rough idle, hesitation, a check‑engine light with mixture or catalyst codes, and sometimes a sulphur smell. A scan showing skewed fuel trims or a lazy sensor response on live data is a strong hint.

Should both sensors be replaced at the same time?

Not necessarily. Replace the sensor that’s failed testing or flagged by diagnostics. If the car has high kilometres and both sensors are original, some owners choose to refresh both, but good diagnostics first will save money and guesswork.