Parts for your 2018 Subaru Exiga-Map sensor

2018 Subaru Exiga MAP sensor — what it does and how to look after it

Based on technical sources, the 2018 Subaru Exiga (sold in Japan as the Exiga Crossover 7 with the FB-series 2.5L engine) is fitted with a manifold absolute pressure (MAP) sensor. The Subaru Factory Service Manual for FB engines describes dual load calculation using both MAF and MAP inputs, and the Subaru FAST parts catalogue lists a “Sensor – Pressure (Manifold Absolute)” for the 2015–2018 Exiga/Crossover 7. DENSO engine management documentation for the FB platform also references MAP input for EGR diagnostics, altitude correction and transient fuelling. So yes—the MAP sensor is relevant and used on this model.

The MAP sensor reads the absolute pressure inside the intake manifold. The ECU uses that signal—alongside the MAF—to figure out engine load, trim fuel, set ignition timing, stabilise idle, and keep things sweet at different altitudes. On the Exiga, it’s mounted directly to the intake manifold near the throttle body with an O-ring seal, so there are no vacuum hoses to perish or crack.

When a MAP sensor starts playing up, the Exiga can feel a bit doughy off the mark, burn more fuel than it should, idle roughly or light the MIL. Common fault codes include P0106 (MAP/Baro range/performance), P0107 (low input) and P0108 (high input). Because the ECU relies on quality pressure data to correct fuelling quickly during throttle changes, a lazy sensor can make the car feel hesitant or hunt at idle.

There’s no fixed replacement interval in Subaru schedules, but it’s smart to inspect and gently clean the MAP sensor every 40,000–60,000 km, or whenever you service the air filter and PCV system. Use an electronics-safe sensor cleaner only—never carby or brake cleaner—and let it air-dry. If the O-ring looks flattened or cracked, replace it. Excess oil mist from a tired PCV valve can contaminate the sensor tip, so keep that in check as well.

If replacement’s on the cards, it’s a simple driveway job:

1. Pop the bonnet, remove the engine cover and disconnect the battery negative if you want trims reset.
2. Locate the MAP on the manifold near the throttle body, unplug the connector.
3. Undo the small retaining bolt, ease the sensor straight out, minding the O-ring.
4. Lightly oil the new O-ring, seat the new sensor squarely, and nip the bolt up—just snug, don’t overdo it.
5. Reconnect, clear any codes, then let it idle to relearn before a short mixed drive.

Genuine Subaru or quality DENSO units are recommended—cheap copies can skew readings and undo all that careful ECU logic.

• Where is the MAP sensor on a 2018 Subaru Exiga?
  Under the bonnet on the intake manifold, close to the throttle body. It’s a small, black, two-bolt or single-bolt sensor with a three-pin plug, pointing into the manifold runner area.
• How do you know if the MAP sensor is failing?
  Look for rough idle, flat spots, higher-than-normal fuel use and a check engine light. Scan tools often show P0106, P0107 or P0108. Live data will show unstable manifold kPa readings compared with expected values at idle and cruise.
• Can a MAP sensor be cleaned, or should it be replaced?
  If it’s just light oil film, a careful clean with electronics-safe sensor spray can bring it back. If there’s internal faulting, cracked housing, or persistently incorrect readings, replacement is the go.