Parts for your 1998 Subaru Forester-Camshaft sensor

1998 Subaru Forester Camshaft Sensor — What it does and when to replace it

Technical sources confirm the 1998 Subaru Forester is fitted with a camshaft position sensor and it is essential to engine management. Subaru’s Factory Service Manual for the SF Forester lists DTC P0340/P0341 (Camshaft Position Sensor Circuit) for MY1998 vehicles, and the Engine section includes test and replacement procedures for the “Camshaft Position Sensor (PHASE)”. Subaru’s Electronic Parts Catalogue also lists a “Sensor – Camshaft Position” (e.g., part no. 22056AA061/22056AA100) as applicable to 1997–1998 Forester SF models. These documents establish that the camshaft sensor is used and relevant on the 1998 Forester.

On the 1998 Forester’s EJ-series boxer engine, the camshaft sensor works with the crank sensor to tell the ECU exactly where the engine is in its cycle. That lets the ECU time spark and fuel injection correctly, especially for sequential injection and smooth starts. If the sensor signal goes missing or messy, the Forester can be hard to start, stumble, misfire, or throw the check-engine light with codes like P0340. In some cases it’ll crank but not fire under the bonnet.

There’s no regular service interval for the cam sensor — it’s a solid-state pickup designed to last — but it does live in a hot spot, and age, vibration, or oil contamination can get to it. It’s mounted at the rear of the left-hand cylinder head near the bellhousing area. Basic care during routine servicing is simple: keep the connector clean and dry, inspect the harness for chafing, and fix any nearby oil leaks that could wick into the plug.

Replacement is a straightforward driveway job for a handy owner. Disconnect the battery, unplug the sensor, remove the single retaining bolt, and pull the sensor straight out. Lightly oil the O-ring on the new unit, seat it squarely, and nip the bolt up to the factory spec — don’t overdo it. Clear any stored fault codes and take it for a run to confirm the fix. If the issue returns, check the crank sensor and wiring loom, as the ECU needs both clean signals to behave properly.

If the Forester is used for long country kilometres or regular towing in Aussie or Kiwi heat, consider inspecting the sensor plug and loom at each major service to get ahead of heat-related gremlins.

• Common symptoms of trouble: hard starting, rough idle, intermittent stalling, poor fuel economy, and a glowing MIL with P0340/P0341.
• Handy tip: a failing cam sensor can mimic ignition coil or fuel issues — scan data and a quick scope test save guesswork.

FAQs

Where is the camshaft sensor on a 1998 Subaru Forester?
It sits at the back of the left-hand cylinder head, up near the firewall side of the engine. Pop the bonnet, look down behind the intake manifold on the driver’s side (RHD models), and you’ll see a small sensor with a single bolt and a two-wire connector.

The location is tight but accessible with a quarter-drive ratchet and a short extension. Always unplug the battery before reaching in around the engine loom.

What are the signs the camshaft sensor is failing on this model?
Expect intermittent hard starts, misfires at low revs, and the check-engine light with codes like P0340. It can also drop into a limp-like behaviour with flat throttle response.

Because the EJ engine relies on both cam and crank signals, a bad cam sensor may allow the car to run but poorly. If it won’t start hot yet starts cold, that’s another classic hint.

Is it safe to drive with a dodgy camshaft sensor?
Short trips to a workshop are usually fine if it still runs, but performance and fuel use will suffer, and it may stall at the worst time. If it’s a no-start or stalls repeatedly, get it towed.

Prolonged driving with faulty timing signals can mask other problems and make diagnosis harder, so it’s best sorted promptly.