Parts for your 2006 Subaru Impreza-Camshaft sensor

2006 Subaru Impreza camshaft sensor — what it does and when to replace it

Based on the Subaru Factory Service Manual for MY2006 Impreza (EJ-series engines), Subaru’s OBD-II Diagnostic manual listing DTCs P0340/P0341/P0345 for camshaft position sensor circuits on 2006 models, and Subaru’s OEM parts catalogue entries for EJ20/EJ25 engines, the 2006 Subaru Impreza is fitted with and uses a camshaft position sensor. Non-turbo SOHC models typically have one sensor, while turbo/AVCS DOHC models (WRX/STI) use two — one per bank.

The camshaft sensor is a key input the ECU relies on for timing fuel injection and spark, and on AVCS-equipped models it also helps the ECU control cam advance. Working in tandem with the crank sensor, it lets the ECU know exactly which stroke each cylinder is on. If it goes out, the ECU may fall back to a limp strategy, starting can take longer, and the engine can feel flat as a tack.

Typical signs the cam sensor needs attention include:

• Check Engine Light with codes like P0340, P0341, P0345 or P0349
• Extended cranking, rough idle, random stalling once warm
• Sluggish performance, poor fuel economy, or AVCS inoperative on WRX/STI

There’s no scheduled replacement interval — it’s a fit-and-forget part unless symptoms or fault codes pop up. As part of regular servicing, it’s smart to inspect the sensor connector and wiring near the rear of the cylinder head(s), especially for heat or oil exposure. Rocker cover seepage can wick into connectors, so fixing minor oil leaks and keeping plugs clean can save headaches. Fresh, correct-grade oil helps AVCS response and reduces false cam/crank correlation dramas.

Replacement is straightforward for a home mechanic with basic tools: disconnect the battery, remove any intake ducting for access, locate the sensor at the back of the cylinder head (one on NA, one per bank on many turbo/AVCS), unplug the connector, undo the retaining bolt, then gently twist and pull the sensor out. Fit a new O-ring, lightly oil it, seat the new sensor, refit the bolt, reconnect the plug, then clear codes and take it for a gentle drive so the ECU can relearn. If choosing parts, an OEM sensor usually avoids intermittent gremlins that cheaper copies can bring.

If a cam sensor code returns straight away, don’t forget the basics: verify crank sensor health, check for timing belt or timing mark issues on belt-driven EJ engines, and on AVCS cars confirm oil pressure and the oil control solenoids are behaving. A quick scan of live data for cam/crank sync and commanded versus actual cam angle will point the right way without guesswork.

Popular questions about the 2006 Subaru Impreza camshaft sensor

Where is the camshaft sensor on a 2006 Impreza?

On most non-turbo models there’s a single sensor mounted at the rear of one cylinder head near the firewall. Turbo/AVCS models like WRX and STI usually have one sensor per bank, also at the back of the heads. Access is under the bonnet from the top, removing the airbox or inlet ducting often makes life easier.

Is it safe to drive with a failing camshaft sensor?

The car will often run but may be hard to start, lack power, and use more fuel. Prolonged driving with misfires can stress the catalytic converter, so it’s best to diagnose and fix it sooner rather than later. On AVCS engines, a failed sensor can disable cam advance on that bank, which really dulls performance.

Do WRX/STI models have two camshaft sensors?

Many 2006 WRX/STI variants with AVCS use two sensors, one for each bank. If one fails, the ECU can shut down AVCS on that side and throw a code (often P0345/P0349). The engine will usually still run, but it won’t feel its best until the faulty sensor or related wiring is sorted.