Parts for your 2022 Subaru Impreza-Ignition coils

2022 Subaru Impreza ignition coils

Ignition coils are absolutely used on the 2022 Subaru Impreza. Technical sources that document this include the Subaru Service Manual (TechInfo) for the 2022MY Impreza with the FB20 2.0‑litre petrol engine (Ignition System section), Subaru’s genuine parts catalogue (which lists four coil‑on‑plug units for this engine), and major ignition component catalogues from Denso and NGK covering 2017–2023 Impreza FB20 models. These sources confirm the vehicle runs a coil‑on‑plug setup—one coil per cylinder.

On this Impreza, each ignition coil’s job is to step the 12V from the battery up to the thousands of volts needed to fire the iridium spark plugs. Being coil‑on‑plug, the coils sit directly over each spark plug, which sharpens spark control, cuts electrical losses from old‑school leads, and helps the engine deliver smooth power and cleaner emissions. The ECU tightly manages each coil’s dwell and monitors misfires, so a weak coil will often trigger a fault code quickly.

There’s no fixed replacement interval for ignition coils, they’re generally a replace‑as‑needed item. During routine servicing—and especially when replacing spark plugs (typically around the 100,000‑kilometre mark in many AU/NZ schedules)—it’s smart to remove the coils and check the boots for carbon tracking, heat cracks, oil contamination, or moisture. A light smear of dielectric grease on the inside of the boots can help sealing. When refitting, seat each coil squarely and torque the retaining bolts to the Subaru spec noted in the service manual.

Common coil trouble signs include rough idle, a stumble under load, poor fuel economy, a flashing check‑engine light, and OBD‑II codes such as P0301–P0304 (cylinder‑specific misfires) or P0351–P0354 (primary/secondary coil circuit faults). Water ingress after a spirited engine bay wash or heavy rain can also upset coils, so keeping the plug tubes dry matters.

If a single coil is faulty, it can usually be replaced on its own. For higher‑kilometre cars or when multiple cylinders show coil‑related issues, replacing the full set can be sensible insurance. Stick with quality OE or OE‑equivalent coils specified for the FB20 engine. Disconnect the battery negative before work, ensure the plug wells are clean and dry, and avoid mixing up connectors. After replacement, clear any stored codes and do a proper road test to confirm everything’s sweet.

• Avoid blasting water into the coil/spark plug area when cleaning the engine bay.
• Fix any rocker cover gasket leaks promptly to keep oil out of the plug wells.
• Use the correct iridium plugs and torque, as per the Subaru service manual.

Are ignition coils a scheduled service item on a 2022 Subaru Impreza?

They’re not a routine replacement item. Coils are inspected during services and typically replaced only if there are symptoms or test results indicating a fault. Many last well past typical plug‑change intervals if the engine is healthy and dry.

How long do ignition coils usually last on this model?

It varies with driving conditions and maintenance, but it’s common for original coils to run for many years and tens of thousands of kilometres. Heat, oil contamination, and moisture are the main coil killers—keep those in check and they tend to last.

Should all four coils be replaced at once?

Replacing just the failed coil is fine for a younger, lower‑kilometre Impreza. If the vehicle has higher kilometres or multiple cylinders are playing up, doing the full set can restore smoothness and reduce future downtime.