Plug Spotlight - Coil Pack Plugs | iWire Subaru Wiring Solutions

In this blog post we talk about Coil Pack Connectors. In a Subaru engine, the coil packs are part of the ignition system. Their job is to create the high voltage needed for each spark plug to ignite the air-and-fuel mixture inside the cylinder.

The basic sequence is:

ECU → Coil Pack → Spark Plug → Combustion

The ECU determines exactly when each cylinder should fire and sends a signal to the appropriate coil pack. The coil pack takes the vehicle's roughly 12-volt electrical supply and transforms it into the much higher voltage needed to jump the gap at the spark plug. iWire describes the coil pack connection as providing the signal that triggers the spark plug to fire.

STOP USING ZIP TIES - this could lead to loose connectors and misfires that ruin your engine over time!

What happens when a Subaru coil pack has a problem?

Common symptoms can include:

Engine misfire
Rough idle
Hesitation under boost or acceleration
Check-engine light
Reduced power
Poor fuel economy

Sometimes the coil itself is fine, but the coil-pack connector is cracked, loose, or deteriorated, which can also cause intermittent misfires. That's one reason iWire recommends inspecting the connectors during misfire diagnosis.

Watch iWire's How To Video on Replacing a Coil Pack Plug

White Coil Pack Plug Replacements

Black Coil Pack Plug Replacements

Purchase a full set of 2 White and 2 Black Coil Pack Plugs Here and Save $$$

Note: White coil pack plugs (cylinders 1 and 2) are located in the front of your Subaru and Black coil pack plugs (cylinder 3 and 4) are located in the back of your Subaru.

Grey Coil Pack Plug Replacements