Parts for your 2000 Subaru Forester-Ignition leads

2000 Subaru Forester ignition leads: what they do and when to replace them

On the 2000 Subaru Forester (SF series, EJ20/EJ25 engines), ignition leads are absolutely used. The Subaru Factory Service Manual for the 2000 model year shows a four-tower external ignition coil with high-tension leads running to each spark plug. Major parts catalogues from NGK and Bosch, as well as workshop references like Haynes, also list dedicated spark plug wire/ignition lead sets for this vehicle. So, this model isn’t coil-on-plug, it relies on a coil pack and proper high-quality ignition leads to fire each cylinder.

On this Forester, the ignition leads carry high voltage from the coil pack to the spark plugs. They’re the unsung heroes of a clean burn—if they’re tired, cracked, or high resistance, you’ll feel it as a misfire under load, rough idle, or sluggish overtakes. In wet weather, weak leads can arc to earth, leading to hard starting and a Check Engine light. Keeping them in good nick helps fuel economy, protects the catalytic converter, and keeps the old girl smooth on long Kiwi and Aussie road trips.

As part of regular servicing, it’s smart to inspect the leads every service and plan replacement about every 5–7 years or roughly 100,000–120,000 kilometres, sooner if you notice misfires, visible cracking, swollen boots, green/white corrosion at the terminals, or if a resistance check shows they’re out of spec. When replacing, go for OE-quality or reputable brands matched to the EJ engine. Swap one lead at a time to avoid mixing up routing, and seat boots firmly on both the coil and plug ends until you feel a positive click. A tiny smear of dielectric grease inside the boots helps sealing and future removal.

Routing matters on the EJ: keep leads clipped in their separators, off hot exhaust components, and away from sharp edges. If leads fail prematurely, give the coil pack a look—hairline cracks or carbon tracking on the towers can mimic bad leads. While you’re under the bonnet, check the spark plugs themselves, tired plugs can overwork even good leads. Pairing fresh plugs with new leads is a top way to restore crisp throttle response and keep emissions tidy.

• Common symptoms: stumble under load, rough idle, increased fuel use, visible arcing at night, and stored misfire codes.
• Service tip: always handle leads by the boot, not the cable, to avoid internal damage.
• After fitting: take it for a gentle test drive and verify no misfire or flickering CEL.

FAQs

Does a 2000 Subaru Forester use ignition leads or coil-on-plug?
It uses ignition leads. The 2000 SF Forester runs a four-tower external coil pack feeding high-tension leads to each spark plug, as outlined in the Subaru Factory Service Manual and supported by major parts catalogues that list wire sets for EJ20/EJ25 engines.

How often should the ignition leads be replaced?
Plan on 5–7 years or about 100,000–120,000 kilometres, with earlier replacement if you notice misfires, poor wet-weather performance, visible cracking, or high resistance. Regular inspection at each service is a good habit.

What happens if the ignition leads are failing—can it harm the car?
Yes. Misfires from weak leads can wash extra fuel into the exhaust, overheating the catalytic converter and reducing its life. You may also see rough running, higher fuel use, and harder starting. Sorting the leads promptly helps protect the cat and restores smooth performance.