Parts for your 1998 Subaru Forester-Ignition leads

1998 Subaru Forester ignition leads

Ignition leads are absolutely relevant on a 1998 Subaru Forester. The SF-series Forester ran EJ-series petrol engines (EJ20/EJ25) with a waste-spark coil pack and four high-tension leads to the spark plugs. This configuration is documented in the Subaru Forester 1998 Factory Service Manual (Ignition System section), Subaru Technical Training materials on EJ-series DIS systems, and Australian/NZ parts catalogues from brands like NGK and Bosch that list complete lead sets for the 1997–2000 Forester range.

The ignition leads on a ’98 Forester do the simple but critical job of carrying high voltage from the centrally mounted coil pack to each spark plug. Good leads keep the spark strong and consistent, so the boxer four fires cleanly and pulls smoothly. When they’re tired, you’ll often notice misfires under load, a rough idle, flat spots, worse fuel economy, and sometimes a ticking or snapping sound under the bonnet if the spark is arcing to earth.

For servicing in Australia and New Zealand, a sensible rule is to replace the leads about every 100,000 km or five years, sooner if the vehicle lives in high heat, dust, or does lots of short trips. During routine services, it’s worth checking the insulation for cracks, hardening, or burn marks, confirming the boots fit snugly, and measuring resistance against the Factory Service Manual specs if you’ve got a multimeter handy. If there’s oil in the plug wells from cam cover gasket seepage, clean that out first—oil contamination shortens lead life.

When swapping them out, do one lead at a time to avoid mixing up cylinder routing. The EJ firing order is 1-3-2-4, and lead layout and clip positions matter to prevent crossfire. Make sure each boot “clicks” onto the plug and coil tower, route the cables in the original retainers away from hot exhaust bits, and use a tiny dab of dielectric grease inside the boots to help sealing and future removal. If the coil pack towers are corroded, clean them or replace the coil—weak towers can chew through new leads quickly.

Stick with quality silicone-jacketed sets from reputable brands sized for the EJ20/EJ25 SF Forester. Pairing new leads with fresh plugs (correct heat range and gap) gives the biggest payoff. A well-sorted ignition under the bonnet keeps the old Forester feeling perky, starts easier on frosty mornings, and protects the catalytic converter by preventing unburnt fuel from misfires.

• Typical signs it’s time: hesitation under load, rough idle, visible arcing, cracked insulation, or green/white corrosion at boots.
• Service tip: inspect leads at every major service, replace as a set for even performance.

Popular questions about 1998 Subaru Forester ignition leads

Which ignition leads fit a 1998 Forester?
Any set specified for the SF-series Forester with EJ20 or EJ25 and a waste-spark coil pack will fit. Use the VIN/engine code to confirm and choose a quality silicone-core set from known brands. Avoid coil-on-plug sets—this model doesn’t use them.

How often should the leads be replaced?
Plan on every 100,000 km or five years in local conditions, sooner if there’s heat exposure, oil contamination, or misfire symptoms. Inspect at each major service and replace as a complete set for best results.

Can bad leads damage other components?
Yes. Persistent misfires can overwork the coil and dump unburnt fuel into the exhaust, which can harm the catalytic converter. Replacing weak leads promptly protects the coil, plugs, and cat.