OEM & aftermarket ignition coil from top brands — compare prices, check fitment, order with free delivery
Ignition coils step up the battery's 12 volts to the 20,000-40,000 volts needed to create a spark at the spark plug. Modern engines use coil-on-plug (COP) designs with one coil per cylinder for precise ignition timing. A faulty coil causes misfires, rough running, increased emissions, and a check engine light. Diagnosing the faulty coil is straightforward with an OBD scanner.
Ignition coil failure typically affects one cylinder at a time. The engine management system detects the misfire and stores a diagnostic trouble code.
Coil-on-plug designs make diagnosis easy: swap the suspected coil with an adjacent cylinder's coil. If the misfire follows the coil, that's your faulty unit.
