Seal the spark path and keep the high-voltage jump from coil to plug clean with the ThunderCore PRO Coil Boot, MPN 900-P2108. It installs as a direct-fit replacement for the 2003-2005 Subaru Impreza, slipping over the spark plug to bridge the ignition coil and the plug terminal.
A coil boot is the insulating sleeve that carries the coil's high-voltage spark down to the spark plug while sealing the plug well against moisture, oil, and debris. Over time boots can harden, crack, or track, letting spark arc to ground — this is a replacement for that worn component.
- Spark transfer: routes high-voltage current from the ignition coil to the spark plug terminal.
- Insulation & sealing: helps insulate the connection and keep the plug well clear of moisture and contaminants.
- Direct fit: designed to install on the listed Subaru Impreza applications.
If a cracked or worn coil boot is the cause of a misfire, rough idle, or visible arcing, this replaces it; diagnose the cause before replacing.
Interchange: 671-4307 · 6714307 · 36-2071 · 362071 · 36-2085 · 362085 · SPP131E · Manufacturer part number 900-P2108 (also 900P2108).
This part cross-references / interchanges with the following part numbers:
671-4307, 36-2071, 36-2085, SPP131E
Frequently Asked Questions
What vehicles does this coil boot fit?
It is a direct-fit replacement for the 2003-2005 Subaru Impreza. Check the "Vehicles it fits" section to confirm it matches your specific vehicle.
What does a coil boot do?
It transfers the ignition coil's high-voltage spark to the spark plug terminal while insulating the connection and helping seal the plug well from moisture and debris.
What are signs my coil boot may need replacing?
Hardened, cracked, or arcing boots can contribute to misfires or a rough idle. Diagnose the cause first, since these symptoms can have other sources.
What is the manufacturer part number?
The ThunderCore PRO manufacturer part number is 900-P2108.
What other part numbers does this replace?
It interchanges with 671-4307, 36-2071, 36-2085, and SPP131E. Match any of these numbers to confirm the correct replacement.
