P0302 Honda Accord: Cylinder 2 Misfire Detected

Quick Answer: What is P0302?

On a Honda Accord, the P0302 code triggers when the Powertrain Control Module (PCM) detects that Cylinder #2 is not contributing enough power to the engine's rotation. This "misfire" means combustion in that specific cylinder is incomplete or non-existent, usually due to a faulty ignition coil or fouled spark plug.

Severity: HIGH. A misfiring cylinder allows raw gasoline to enter your exhaust, which can overheat and melt your catalytic converter (a $1,500+ repair). If your Check Engine Light is flashing, pull over safely and stop the engine.

Common Symptoms

Engine Shaking: Noticeable vibration at idle or while stopped in gear.
Loss of Power: The car feels "sluggish" during acceleration or climbing hills.
Stalling: The engine may shut off when coming to a stop.
Strong Gas Smell: Unburned fuel exiting the exhaust pipe.

Most Likely Causes

Failed Ignition Coil (70%): The coil on plug for cylinder 2 has failed internally.
Worn-out Spark Plug (20%): Excessive gap or carbon buildup preventing a strong spark.
Fuel Injector Issue (7%): Cylinder 2 isn't receiving enough fuel.
Engine Mechanical (3%): Low compression due to a burnt valve or worn piston rings.

Detailed Repair Cost & Labor Breakdown

Below is a specific breakdown of costs for the Honda Accord (4-cylinder and V6 models):

Component / Task	Aftermarket Part	OEM Honda Part	Labor Time	Difficulty
Ignition Coil (Denso/NGK)	$45 - $70	$110 - $145	0.3 hrs	Very Easy
Iridium Spark Plugs (Set)	$35 - $50	$80 - $110	0.8 - 1.5 hrs	Moderate
Fuel Injector (Cyl 2)	$75 - $120	$190 - $260	2.0 - 3.0 hrs	Hard

Step-by-Step Fix

Step 1: The Coil Swap Test

Honda ignition coils are easy to reach. Swap the coil from Cylinder #2 with the coil from Cylinder #1. Clear the code and drive. If the new code is P0301, the coil is dead. If it stays P0302, move to the spark plug.

Step 2: Inspect Spark Plug #2

Remove the spark plug and check for "oil fouling" or a cracked ceramic tip. If the plug is black and wet with oil, you may have a leaking valve cover gasket that is shorting out the spark.

Step 3: Check Connector Wiring

Ensure the electrical connector for the coil isn't brittle or broken. Honda engine heat can make these plastic clips fail, causing the coil to vibrate loose.