Worn or fouled spark plug on cylinder 1; Failed ignition coil or coil-on-plug boot for cylinder 1; Faulty fuel injector for cylinder 1 (clogged, leaking, or electrically open); Vacuum leak at the intake manifold runner or gasket near cylinder 1; Low compression on cylinder 1 due to worn rings, valve issues, or head gasket failure; Damaged wiring or connector to the cylinder 1 injector or coil; Mechanical fault such as a worn camshaft lobe or collapsed lifter affecting cylinder 1

DTC codes / Nissan codes / P1301

P1301 · NissanCylinder 1 Misfire

Q: What does code P1301 mean?

Cylinder 1 Misfire. P1301 on Nissan vehicles indicates that the engine control module (ECM) has detected a misfire specifically on cylinder 1, meaning that cylinder is not contributing its fair share of power to the engine. The ECM monitors crankshaft speed fluctuations and flags this code when the misfire rate exceeds a calibrated threshold, often within a specific RPM or load window.

P1301 on Nissan vehicles indicates that the engine control module (ECM) has detected a misfire specifically on cylinder 1, meaning that cylinder is not contributing its fair share of power to the engine. The ECM monitors crankshaft speed fluctuations and flags this code when the misfire rate exceeds a calibrated threshold, often within a specific RPM or load window.

SystemPowertrain

Code typeNissan specific

SeverityHigh

Fix difficultyIntermediate

AreaIgnition system and misfire

Symptoms you may notice

Check engine light illuminated, often flashing if the misfire is severe enough to damage the catalytic converter
Noticeable engine shake or vibration at idle, especially when cold
Rough running or hesitation during acceleration
Loss of power and reduced fuel economy
Often no symptoms besides the warning light when the misfire is intermittent or mild
A distinct exhaust note that may sound uneven or 'lumpy'

Common causes, most likely first

Worn or fouled spark plug on cylinder 1
Failed ignition coil or coil-on-plug boot for cylinder 1
Faulty fuel injector for cylinder 1 (clogged, leaking, or electrically open)
Vacuum leak at the intake manifold runner or gasket near cylinder 1
Low compression on cylinder 1 due to worn rings, valve issues, or head gasket failure
Damaged wiring or connector to the cylinder 1 injector or coil
Mechanical fault such as a worn camshaft lobe or collapsed lifter affecting cylinder 1

How to diagnose and fix it

Scan all stored and pending codes and freeze-frame data to confirm the misfire is isolated to cylinder 1 and note the conditions under which it occurs
Perform a visual inspection of the cylinder 1 ignition coil, spark plug, and injector connectors for damage, corrosion, or oil contamination
Swap the ignition coil and spark plug from cylinder 1 with a known-good cylinder and see if the misfire moves, confirming a faulty component
Check spark plug condition and gap, replacing plugs if worn or fouled, and inspect the coil boot for carbon tracking
Test the cylinder 1 fuel injector for resistance and pulse signal using a noid light or oscilloscope, and check fuel pressure
Run a compression test and, if low, a cylinder leak-down test to rule out mechanical faults before replacing ignition or fuel parts
Smoke-test the intake system for vacuum leaks and repair any broken hoses or gaskets near cylinder 1

What Nissan techs check before replacing parts

A flashing check engine light with P1301 means the misfire is severe enough to dump raw fuel into the catalytic converter, which can melt the substrate in minutes; stop driving and fix it immediately.
Nissan coil-on-plug boots often develop carbon tracking that causes misfires only under high load or damp conditions, so a visual inspection alone can miss a failing coil.
A clogged or failing fuel injector on cylinder 1 is a common cause on older Nissan engines, but many technicians replace coils first because they are easier to access; always test injector pulse and resistance before buying parts.
A vacuum leak at the intake manifold gasket can lean out cylinder 1 specifically, setting a misfire code without any ignition or fuel component being faulty.
Low compression from a worn valve seat or piston ring can set P1301, and swapping coils or plugs will not fix it; a compression test is the only way to rule out a mechanical cause.

Can I keep driving with P1301?

If the check engine light is flashing, stop driving immediately and have the vehicle towed to avoid catalytic converter damage. If the light is steady and the misfire is mild, you can drive cautiously to a repair shop, but avoid heavy acceleration and prolonged driving until the fault is repaired.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for Nissan vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.