Parts for your 2017 Subaru Exiga-Ignition coils

2017 Subaru Exiga ignition coils — what they do and when to replace them

Based on Subaru’s own technical literature for the FB‑series boxer engines — notably the Subaru service manual Ignition System section for the FB engine family and Subaru’s New Car Features/technology guides — the 2017 Subaru Exiga (sold in its later years as the Crossover 7 in Japan) runs a direct ignition system with individual coil‑on‑plug units for each cylinder. Because that model is petrol‑powered and uses an FB‑series flat‑four, ignition coils are absolutely fitted and relevant to servicing.

On this Exiga, each ignition coil sits directly on top of its spark plug. The coil’s job is to step the 12‑volt battery supply up to the thousands of volts needed to fire the plug, lighting the air‑fuel mix right on time. Coil‑on‑plug keeps the spark strong and precise, helps cold starts, and cuts down on electrical losses you’d get with old‑school leads.

When coils get tired, the Exiga will usually tell on itself: rough idle, hesitation under load, worse fuel use, hard starting and a check‑engine light with misfire fault codes (often P0301–P0304). Left unfixed, ongoing misfire can hammer the catalytic converter, so it’s worth sorting promptly.

There’s no scheduled replacement interval for coils on this model — they’re replaced on condition. During regular servicing, it’s smart to:

• Scan for misfire codes and look at live misfire counters.
• Inspect coil connectors and boots for corrosion, oil intrusion or cracking (rocker cover gasket leaks can wick oil into the plug tubes).
• Change spark plugs at the recommended interval and apply a light smear of dielectric grease to the coil boots when refitting.

Replacement is straightforward: pop the bonnet, remove the engine cover, disconnect the coil’s plug, undo the retaining bolt, twist and lift the coil off the plug, then refit the new unit and click the connector home. Always torque fasteners and spark plugs to the figures in Subaru’s service manual, and stick with genuine or reputable-brand coils for consistent dwell control and heat resistance. If one coil has failed on a high‑kilometre Exiga, many workshops suggest replacing the full bank or all four to keep things even, especially if the plugs are due as well.

Look after the coils and plugs, and the FB‑series boxer will reward with smooth, efficient motoring across plenty of Kiwi and Aussie kilometres.

Popular questions about 2017 Subaru Exiga ignition coils

How long do ignition coils typically last on a 2017 Exiga?

There isn’t a fixed lifespan, but it’s common to see original coils run well past 100,000–150,000 km. Heat, oil contamination and poor plugs can shorten their life. If the car is misfiring or logging coil‑related codes, test and replace as needed rather than waiting for a set interval.

Is it okay to keep driving with a misfiring coil?

Not ideal. A short drive to the workshop is usually fine, but extended driving on a misfire can overheat and damage the catalytic converter, wash cylinders with unburnt fuel, and strain the rest of the ignition system. Best to diagnose and fix promptly.

Do all four coils need replacing at once?

Not necessarily. Many technicians replace the single failed coil after confirming the fault (often with a swap test). On higher‑kilometre cars, doing coils in pairs or all four can prevent a game of whack‑a‑mole, especially if plugs are due and access time is a factor.