Parts for your 2012 Subaru Forester-Map sensor

2012 Subaru Forester MAP sensor: what it does, where it is, and how to look after it

Yes, a MAP (Manifold Absolute Pressure) sensor is fitted to the 2012 Subaru Forester and it’s definitely relevant to how the engine runs. Subaru’s own 2012 Forester (SH) Service Manual on the Subaru Technical Information System (STIS) includes MAP sensor circuit diagnostics for both the FB25 2.5‑litre non‑turbo and the EJ255 turbo engines, and the Subaru Genuine Parts catalogue lists a MAP sensor for these variants (commonly referenced under Subaru p/n 22012‑ series, OE by Denso). Denso’s application data also lists a manifold pressure sensor for 2012 Forester engines. Those technical sources make it clear the car uses both a MAF and a MAP: the MAF measures incoming air at the airbox, while the MAP reads pressure in the intake manifold for load calculation, transient fueling and diagnostics—and on turbo models, for boost control.

On a 2012 Forester, the MAP sensor’s job is to tell the ECU what the manifold pressure is right now, so fueling and ignition timing can be trimmed on the fly. On FB25 models it sharpens throttle response and helps detect issues like vacuum leaks. On EJ255 turbo models it’s also a key input for boost control and knock protection. When the MAP goes out of whack, drivers often see rough idle, flat spots, higher fuel use, or fault codes like P0106.

There’s no scheduled replacement interval, but a quick check each service (say every 10,000–15,000 km) is smart. Under the bonnet, the MAP sensor sits on the intake manifold near the throttle body (turbo models may mount it on or just off the manifold in easy reach). If the car idles lumpy or feels doughy, it’s worth inspecting the sensor port for oil vapour residue or carbon. Use non‑residue electronics cleaner and let it dry—don’t poke anything into the port. Make sure the O‑ring isn’t torn, and that the connector is clean and clipped in firmly.

Replacement is straightforward: disconnect the battery, unplug the connector, remove the retaining screw(s), swap the sensor, lightly lube the O‑ring, refit, and tighten to factory spec. Clear any codes with a scan tool and confirm live MAP readings look sensible at key‑on (roughly ambient barometric pressure) and at idle (lower than ambient). For turbo models, incorrect MAP data can cause under/over‑boost, so don’t ignore MAP‑related faults—sort them before spirited driving or towing.

• Common signs: sluggish response, poor economy, rough idle, check‑engine light (e.g., P0106/P0107/P0108), or boost control issues (turbo).
• Good practice: inspect at each service, clean only with electronics cleaner, and replace the O‑ring if flattened or cracked.

Popular questions

Does a 2012 Forester have both a MAF and a MAP sensor?
Yes. The MAF sits at the airbox to measure incoming air, while the MAP is on the intake manifold to read manifold pressure. Subaru’s 2012 Forester service information documents diagnostics for both sensors across FB25 and EJ255 engines.

Where is the MAP sensor on a 2012 Subaru Forester?
It’s mounted on the intake manifold near the throttle body on non‑turbo models. On turbo variants it’s also on or near the manifold, easy to spot with a three‑pin plug and a small retaining screw.

Can a dirty MAP sensor cause rough idle and high fuel use?
It can. Oil mist and carbon can skew readings, leading to rich running or hesitation. A careful clean with electronics cleaner often restores normal behaviour, if readings stay off, replace the sensor and the O‑ring.