P0301 on Acura
Cylinder 1 Misfire Detected
P0301 on Acura vehicles indicates cylinder 1 misfire detected. Au7o has documented this code across 4 Acura models — most commonly on Integra, MDX, RL. P0301 means the engine computer detected a misfire specifically in cylinder 1 — the spark didn't ignite the fuel properly, or the fuel/air mix didn't burn as it should. The computer detects this by sensing tiny variations in crankshaft speed each time a cylinder fires. A misfire wastes fuel, raises emissions, and can damage the catalytic converter if it's severe or persistent (a flashing check engine light usually warns of active, converter-damaging misfires). Because the code points to one specific cylinder, the cause is usually an ignition, fuel, or compression problem isolated to that cylinder. Typical repair costs on Acura range from $80 to $4,500, depending on the specific model and root cause.
Common Causes of P0301
- •Worn or fouled spark plug in cylinder 1
- •Failed ignition coil or coil pack for cylinder 1
- •Faulty or clogged fuel injector for cylinder 1
- •Vacuum or intake air leak affecting that cylinder
- •Bad spark plug wire (on applicable engines)
- •Low compression (worn rings, leaking or burnt valve, head gasket)
- •Carbon buildup on intake valves
- •Wiring or connector fault to the coil or injector
P0301 on Acura by Model
Acura Integra(1 issue)
- Distributor internal shaft seal fails, oil leaks into cap and causes misfires + stalling1990-2001
The ignition distributor on 1990-2001 Integras (and all Honda B-series engines of the era) sits at the rear of the head and is driven directly off the exhaust cam. Inside the distributor housing, an oil seal separates the cam-driven shaft from the cap/rotor/electrical assembly above it. When this seal hardens with age and heat cycling, engine oil under pressure leaks past the shaft, fills the cap area, and coats the rotor and contacts. Result: misfires, hard starts, hesitation, stalling at idle, and sometimes a check-engine light for misfire codes. The shaft seal CAN technically be replaced internally, but it is difficult and many shops will not attempt it — they replace the whole distributor instead because reused housings often re-leak quickly. Cleaning the cap helps for a few weeks and then symptoms return.
Acura MDX(1 issue)
- VCM-Related Oil Consumption, Spark Plug Fouling and Motor Mount Failure (J37 VCM Engine)2010-2013
Variable Cylinder Management (VCM) on the J37A1 3.7L V6 deactivates one bank of three cylinders under light load. Over time the deactivated cylinders burn oil past the rings, fouling plugs, and the constant 6-3-6 cylinder transition prematurely wears the hydraulic Active Control Engine Mounts (front + rear). Subject of a class-action settlement (Soto v. American Honda) covering 2010-2013 MDX, 2011-2012 RL, 2009-2014 TL and 2010-2013 ZDX with the J37 engine.
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.
Looking for P0301 on a different make?
View P0301 across all makes →Frequently Asked Questions
What does P0301 mean on Acura?▼
P0301 stands for "Cylinder 1 Misfire Detected." P0301 means the engine computer detected a misfire specifically in cylinder 1 — the spark didn't ignite the fuel properly, or the fuel/air mix didn't burn as it should. The computer detects this by sensing tiny variations in crankshaft speed each time a cylinder fires. A misfire wastes fuel, raises emissions, and can damage the catalytic converter if it's severe or persistent (a flashing check engine light usually warns of active, converter-damaging misfires). Because the code points to one specific cylinder, the cause is usually an ignition, fuel, or compression problem isolated to that cylinder. On Acura specifically, this code is documented across 4 models.
What causes P0301 on Acura vehicles?▼
Common causes on Acura: Worn or fouled spark plug in cylinder 1, Failed ignition coil or coil pack for cylinder 1, Faulty or clogged fuel injector for cylinder 1, Vacuum or intake air leak affecting that cylinder, Bad spark plug wire (on applicable engines). Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0301 on a Acura?▼
Repair costs on Acura range from $80 to $4,500, depending on the specific model and root cause.
Which Acura models have P0301 documented?▼
Au7o has documented P0301 on 4 Acura models: Integra, MDX, RL, TL.