NGK 2308 Spark Plug

NGK CPR9EA-9 Spark Plug for Reliable Ignition

NGK 2308 is a standard spark plug built for consistent ignition performance in a wide range of domestic and import applications. As part of the NGK Standard Spark Plug line, this plug uses a copper center electrode with nickel tip materials and a standard ground electrode design for dependable spark delivery.

Fits 2006-2011 Honda Civic, and other applications that call for NGK CPR9EA-9. It is also a direct reference for part number 2308.

Key Features

• Part number: 2308 / CPR9EA-9
• Standard spark plug design for OE-style replacement service
• Copper center electrode core material
• Nickel center and ground electrode tip materials
• 5,000 ohm resistance for ignition system noise control
• Pre-gapped at .036 inch
• 10 mm thread diameter with 5/8 inch hex size
• Flat seat and .75 inch reach
• Heat range 9

Product Details

NGK’s Standard Spark Plug line is built around original equipment service standards and broad vehicle coverage. The CPR9EA-9 configuration combines a copper core for efficient heat transfer with nickel electrode materials for stable firing characteristics. With a stud terminal, standard ground configuration, and single ground electrode, this plug is suited to engines that specify this exact heat range and dimensions.

For shoppers searching for NGK 2308 spark plug, CPR9EA-9 replacement, or a spark plug for Honda Civic applications, this part provides the specifications needed for direct-match service where listed by the vehicle manufacturer.

Common Issues This Part Can Address

• Hard starting caused by worn spark plug electrodes
• Rough idle from inconsistent spark delivery
• Misfire conditions related to plug wear or incorrect heat range
• Reduced fuel efficiency from degraded ignition performance
• Engine hesitation under load when the existing plug is past service life

Installation Notes and Tips

Verify the engine calls for NGK CPR9EA-9 before installation. Confirm thread diameter, reach, seat type, and pre-gap specification against the service manual for the vehicle. Use proper spark plug removal and installation procedures to avoid cross-threading the cylinder head, and check ignition system condition if misfire symptoms remain after replacement.

Quality Assurance

NGK is a long-established OE supplier with extensive coverage across automotive, motorcycle, marine, and small engine applications. The 2308 spark plug is manufactured to support original equipment standards for durability and consistent operation in specified applications.

This part cross-references Honda OEM 31926-KRM-841 for the same application.