P0306 on Acura
Cylinder 6 Misfire Detected
P0306 on Acura vehicles indicates cylinder 6 misfire detected. Au7o has documented this code across 2 Acura models — most commonly on RL, TL. This code means the engine computer detected a misfire on cylinder 6 — that cylinder isn't burning its fuel-air mixture properly. The computer senses misfires by watching for tiny variations in crankshaft speed each time a cylinder should fire, and when cylinder 6 repeatedly fails to contribute, this code sets. You may feel a shake or stumble, especially at idle or under load, along with reduced power and possibly a flashing check-engine light, which signals a misfire severe enough to damage the catalytic converter. A misfire comes down to a problem with spark, fuel, or compression in that cylinder. Typical repair costs on Acura range from $100 to $4,500, depending on the specific model and root cause.
Common Causes of P0306
- •Worn or fouled spark plug on cylinder 6
- •Failed ignition coil for cylinder 6
- •Clogged, leaking, or failed fuel injector
- •Vacuum or intake air leak affecting that cylinder
- •Low compression (worn rings, burnt valve, head gasket)
- •Damaged plug wire or coil connector
- •Carbon buildup or worn valvetrain components
P0306 on Acura by Model
Acura RL(1 issue)
- Distributor shaft seal leaks oil into cap, causes misfires (P0300-P0304) on 3.5L C35A1996-2004
Like every C-series V6 Honda used in the 1990s and 2000s (Legend, NSX, CL, TL, RL all share the family), the RL's 3.5L C35A V6 has a distributor mounted at the back of the head and driven directly off the camshaft. Inside the distributor housing, an oil seal isolates the cam-driven shaft from the cap/rotor/electrical assembly above. By 100,000 miles the seal hardens, oil pressure forces engine oil past the shaft, and the cap fills with oil. Result: misfires (typically P0300 random plus individual cylinder codes P0301-P0306 since this is a V6), rough idle, hesitation. RepairPal explicitly lists distributor O-rings as one of the most common Acura RL oil leak points. The figure-8 oil cooler seal and oil filter housing gasket are the other two common leaks on this engine — diagnose carefully before assuming distributor. The C35A engine remained in the first-gen RL through the entire 1996-2004 production run, so this issue affects all years.
Acura TL(1 issue)
- Oil Consumption and Fouled Spark Plugs on 3.7L V62009-2014
The 3.7L J37 V6 used in many TL SH-AWD models has a documented pattern of excessive oil consumption, sometimes leading to low oil level warnings, misfires, and spark plug fouling. Acura/Honda issued warranty extensions and service information for affected V6 engines in this family due to piston ring-related oil consumption. Owners often notice the engine using significant oil between changes, and if ignored, the condition can progress to rough running and catalyst damage risk.
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View P0306 across all makes →Frequently Asked Questions
What does P0306 mean on Acura?▼
P0306 stands for "Cylinder 6 Misfire Detected." This code means the engine computer detected a misfire on cylinder 6 — that cylinder isn't burning its fuel-air mixture properly. The computer senses misfires by watching for tiny variations in crankshaft speed each time a cylinder should fire, and when cylinder 6 repeatedly fails to contribute, this code sets. You may feel a shake or stumble, especially at idle or under load, along with reduced power and possibly a flashing check-engine light, which signals a misfire severe enough to damage the catalytic converter. A misfire comes down to a problem with spark, fuel, or compression in that cylinder. On Acura specifically, this code is documented across 2 models.
What causes P0306 on Acura vehicles?▼
Common causes on Acura: Worn or fouled spark plug on cylinder 6, Failed ignition coil for cylinder 6, Clogged, leaking, or failed fuel injector, Vacuum or intake air leak affecting that cylinder, Low compression (worn rings, burnt valve, head gasket). Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0306 on a Acura?▼
Repair costs on Acura range from $100 to $4,500, depending on the specific model and root cause.
Which Acura models have P0306 documented?▼
Au7o has documented P0306 on 2 Acura models: RL, TL.