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Parts for your 2008 Subaru Forester-Map sensor
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2008 Subaru Forester MAP sensor: what it does and how to look after it
Yes, the 2008 Subaru Forester is fitted with a Manifold Absolute Pressure (MAP) sensor. Subaru’s Factory Service Manual (FSM) for the 2008 Forester lists the MAP sensor and associated diagnostics (DTCs P0106–P0108) within the Engine Control section, and the Subaru Electronic Parts Catalogue identifies a manifold pressure sensor across both EJ253 (non‑turbo) and EJ255 (turbo/XT) engines. Denso’s OE parts catalogue also specifies a matching MAP sensor for this model. So it’s absolutely relevant on Aussie and Kiwi‑spec cars.
The MAP sensor tracks the absolute pressure inside the intake manifold. The ECU uses that signal to work out engine load, trim fuelling and spark timing, adjust for altitude, and—on XT models—manage boost. Even on the non‑turbo, it works alongside the MAF as a cross‑check and to sharpen transient response, so a crook MAP can make the car feel flat, surgey, or thirsty.
Typical clues include hard starting, rough idle, black smoke, sluggish hills, and fault codes like P0106, P0107 or P0108. Because it reads pressure at the manifold, oil mist or carbon can foul the sensing port. It’s not a scheduled replacement item, but it’s smart to inspect it whenever the throttle body is serviced or the intake is off under the bonnet.
Quick service tips:
- Locate the MAP on the intake manifold near the throttle body and unplug the connector.
- Remove the fasteners and lift the sensor straight out—don’t lose or pinch the O‑ring.
- If dirty, mist the tip with plastic‑safe electronics cleaner, don’t poke the port, let it air‑dry.
- Refit with a fresh O‑ring if nicked, tighten to the factory torque, reconnect, clear codes, and allow an ECU relearn (idle a few minutes, then a gentle drive over mixed speeds).
When replacing, stick with genuine Subaru/Denso. Cheap copies can be a few kPa off in calibration, enough to upset fuelling and timing. Check the loom for brittle insulation and make sure the manifold passage isn’t blocked. On XT models, also confirm there are no boost leaks that could mislead the sensor.
If the Forester runs sweet and logs no faults, leave it be. But if fuel economy tanks, the idle hunts, or it pings under load, a quick MAP check beats hours of guesswork and keeps the kilometres rolling without drama.
Popular questions about the 2008 Subaru Forester MAP sensor
Does a 2008 Forester have both a MAF and a MAP sensor?
Yes. The non‑turbo and turbo models use a MAF for primary airflow measurement and a MAP for manifold pressure. The ECU blends these inputs for accurate load calculation, altitude correction, and, on XT models, boost control and protection.
How often should the MAP sensor be cleaned or replaced?
There’s no set interval. Inspect it whenever the throttle body is cleaned or if drivability issues or MAP‑related codes appear. Replace only if it’s faulty or contaminated beyond recovery, always use an OE‑quality part and a good O‑ring.
Is it safe to drive with a dodgy MAP sensor?
The car may run in a fallback strategy, but expect poor economy, sluggish response, and potential catalyst stress from rich mixtures. Best to diagnose and sort it promptly rather than rack up kilometres in limp mode.
