Parts for your 2020 Mitsubishi Eclipse cross-Oxygen sensor

2020 Mitsubishi Eclipse Cross oxygen-sensor: purpose, care, and replacement

Yes, the 2020 Mitsubishi Eclipse Cross uses oxygen-sensors. Technical documentation backs this up: the Mitsubishi Eclipse Cross (GK/GL series) Service Manual for 2018–2020 details both a front air–fuel ratio (A/F) sensor and a rear heated oxygen-sensor in the engine control section, Mitsubishi’s ASA parts catalogue lists these sensors by model, and ADR 79/04 (Euro 5-equivalent) emissions rules necessitate closed-loop lambda control using oxygen-sensing. On the 1.5‑litre turbo petrol sold in Australia and New Zealand, there’s a wideband A/F sensor upstream of the catalytic converter and a conventional heated O2 sensor downstream.

On this Eclipse Cross, the oxygen-sensor family helps the ECU fine‑tune fuelling for smooth running, decent power, and low emissions. The upstream A/F sensor continually measures how rich or lean the exhaust is so the ECU can keep the mixture right on the money, while the downstream O2 sensor monitors catalytic converter efficiency. When they’re healthy, owners see better economy, cleaner tailpipe emissions, and fewer drivability niggles.

There isn’t a fixed replacement interval in Mitsubishi’s schedule, but in the real world these sensors are consumables. By around 160,000 km, response can slow or readings can drift. During routine servicing of a 2020‑Mitsubishi‑Eclipse‑Cross oxygen-sensor, it’s smart to:

• Scan for codes (e.g., P0134, P0135, P0138, P0141) and check short/long‑term fuel trims.
• Inspect the harness and connector boots for heat damage or oil ingress.
• Check for exhaust leaks ahead of the sensors—any leak skews readings.
• Avoid silicone sprays, leaded fuels, or coolant/oil contamination that can poison the sensing element.

Replacement is straightforward with the right tools: a proper O2-sensor socket, penetrating oil on a warm (not hot) exhaust, and care with the threads. Use genuine or OEM‑equivalent sensors (the upstream wideband and downstream sensor are not interchangeable), apply the supplied anti‑seize if specified, torque to spec, and route the loom away from heat. After fitting, clear codes, and perform any idle/ECU relearn procedure the service manual calls for so trims settle quickly.

If the Eclipse Cross starts drinking more fuel, idles rough, or throws a check‑engine light, don’t ignore it—an out‑of‑range sensor can take the catalytic converter with it. A quick diagnostic and timely sensor swap is far cheaper than a new cat and keeps the car compliant with Aussie and Kiwi emissions rules.

Popular questions

How many oxygen-sensors does a 2020 Eclipse Cross have and where are they?
Most 1.5T petrol models in AU/NZ have two: an upstream wideband air–fuel ratio sensor in the exhaust manifold area before the catalytic converter, and a downstream heated oxygen-sensor after the cat to monitor its performance.

When should the oxygen-sensors be replaced?
They’re not a scheduled item in Mitsubishi’s service book, but many technicians suggest testing or replacing around 160,000 km, or earlier if there are fault codes, poor economy, or sluggish response on a scan. Always diagnose first—sometimes an exhaust leak or a wiring issue is the real culprit.

Can an oxygen-sensor be cleaned, or should it be replaced?
Cleaning usually doesn’t restore a worn or contaminated sensor, and chemicals can ruin the element. If tests show it’s lazy or out of spec, replacement with a correct-spec sensor is the reliable fix.