Parts for your 2020 Subaru Impreza-Map sensor

2020 Subaru Impreza MAP sensor — what it does and how to look after it

Based on technical references — including the Subaru 2020MY Impreza Service Manual (Engine Diagnostics, ECM DTCs P0106–P0108 for the Manifold Absolute Pressure sensor), Subaru’s FAST parts catalogue for the 2020 Impreza (FB20 engine), and Subaru Select Monitor (SSM) data lists that display Manifold Absolute Pressure — the 2020 Subaru Impreza is fitted with and actively uses a MAP sensor mounted on the intake manifold.

On the 2020 Impreza, the MAP sensor measures absolute pressure in the intake manifold so the ECU can work out engine load. Together with the MAF signal, throttle angle and engine speed, it helps the ECU fine‑tune fuel delivery and ignition timing, manage EGR flow, and adjust for altitude. Under the bonnet, that translates to smooth idle, crisp throttle response and the best possible economy for everyday driving around Aotearoa and Australia.

There’s no routine replacement interval for the MAP sensor, but it should be checked during major services (every 30,000–40,000 km or if drivability issues pop up). Typical signs of a dodgy MAP sensor include:

• Hard starting, stalling or rough idle
• Sluggish performance and higher fuel use
• Ping/knock under load or surging on light throttle
• Check Engine Light with codes like P0106, P0107 or P0108

Quick driveway checks are handy. With the key on/engine off, live data should show close to local barometric pressure (around 100 kPa at sea level). At hot idle, most healthy FB20 engines read roughly 25–40 kPa. If numbers look odd, confirm there are no split vacuum hoses or intake leaks first — they can throw the reading off and mimic a sensor fault.

Replacement is straightforward if testing confirms the sensor is cactus. Use an OE-quality part and:

• Disconnect the battery and remove the engine cover.
• Unplug the MAP connector, undo the retaining screw/bolt.
• Withdraw the sensor carefully, inspect and replace the O‑ring.
• Seat the new sensor squarely, nip up the fastener to spec (don’t overtighten into the plastic manifold).
• Clear fault codes and let the ECU relearn with a short, mixed drive.

Avoid aggressive solvents down the sensor port, if cleaning is needed, only use electronics-safe cleaner sparingly and allow it to dry fully. Keeping the intake tract sealed and the PCV system healthy will help the MAP sensor live a long, drama-free life in your 2020 Subaru Impreza.

Where is the MAP sensor on a 2020 Subaru Impreza?

It’s typically on the top of the intake manifold near the throttle body. Look for a small, rectangular sensor with a single electrical connector and an O‑ring seal, held by one or two bolts. Access is under the engine cover with the bonnet up.

Does a 2020 Impreza have both MAF and MAP sensors?

Yes. The Impreza’s ECU primarily uses the MAF for airflow measurement and the MAP for manifold pressure/load, altitude compensation and diagnostics. Using both signals improves accuracy across different driving and weather conditions.

Do MAP sensors need calibration after replacement?

No special calibration is required. After installing a quality sensor, clear any codes and let the ECU relearn. An idle stabilisation period and a short drive with varied load and speed usually sorts it.