A worn or fouled spark plug in cylinder 4, especially on BMW engines with extended service intervals.; A failed ignition coil for cylinder 4, a very common failure on BMW inline-six and V8 engines.; A leaking or clogged fuel injector for cylinder 4, causing an incorrect air-fuel mixture.; A vacuum leak near cylinder 4, such as a cracked intake manifold gasket or a deteriorated crankcase vent valve.; Low compression in cylinder 4 from worn piston rings, a burned valve, or a failed head gasket.; A faulty wiring harness or connector at the cylinder 4 ignition coil or injector.; Mechanical valvetrain issues such as a worn camshaft lobe or a collapsed lifter on cylinder 4.

DTC codes / BMW codes / P1349

P1349 · BMWMisfire Cylinder 4 With Fuel Cut-off

Q: What does code P1349 mean?

Misfire Cylinder 4 With Fuel Cut-off. P1349 on a BMW means the engine control module has detected a misfire on cylinder 4 severe enough to protect the catalytic converter by cutting fuel to that cylinder. The computer monitors crankshaft speed fluctuations and, once the misfire threshold is exceeded, disables the injector for cylinder 4 and stores this code.

P1349 on a BMW means the engine control module has detected a misfire on cylinder 4 severe enough to protect the catalytic converter by cutting fuel to that cylinder. The computer monitors crankshaft speed fluctuations and, once the misfire threshold is exceeded, disables the injector for cylinder 4 and stores this code.

SystemPowertrain

Code typeBMW specific

SeverityHigh

Fix difficultyIntermediate

AreaIgnition system and misfire

Symptoms you may notice

The check engine light or service engine soon light is illuminated, often flashing while the misfire is active.
The engine may run rough, shake, or feel down on power, especially under acceleration or load.
A noticeable loss of power and reduced fuel economy because cylinder 4 is not contributing.
The exhaust may smell of raw fuel or the catalytic converter may overheat if the misfire persists.
In some cases there are no symptoms besides the warning light, particularly at light throttle or idle.
The engine may enter limp mode or limit rpm to protect the catalytic converter.

Common causes, most likely first

A worn or fouled spark plug in cylinder 4, especially on BMW engines with extended service intervals.
A failed ignition coil for cylinder 4, a very common failure on BMW inline-six and V8 engines.
A leaking or clogged fuel injector for cylinder 4, causing an incorrect air-fuel mixture.
A vacuum leak near cylinder 4, such as a cracked intake manifold gasket or a deteriorated crankcase vent valve.
Low compression in cylinder 4 from worn piston rings, a burned valve, or a failed head gasket.
A faulty wiring harness or connector at the cylinder 4 ignition coil or injector.
Mechanical valvetrain issues such as a worn camshaft lobe or a collapsed lifter on cylinder 4.

How to diagnose and fix it

Scan all stored codes and freeze-frame data, then record the misfire counters for each cylinder to confirm cylinder 4 is the only affected cylinder.
Inspect the cylinder 4 spark plug for wear, fouling, or incorrect gap, and replace it if it does not meet BMW specifications.
Swap the cylinder 4 ignition coil with a known-good coil from another cylinder and recheck misfire counters to see if the misfire moves.
Perform a fuel injector balance test or swap the cylinder 4 injector with another cylinder to check for a fuel delivery fault.
Check for vacuum leaks around the intake manifold and cylinder 4 intake port using a smoke machine or carburetor cleaner.
Run a compression test and, if low, a cylinder leak-down test on cylinder 4 to rule out mechanical faults.
Inspect the wiring and connectors at the cylinder 4 coil and injector for corrosion, chafing, or loose pins.

Why cylinder 4 misfires are often misdiagnosed

A P1349 with fuel cut-off does not always mean the injector is faulty; BMW cuts fuel as a protective strategy, so the root cause is usually ignition or compression related.
On many BMW engines, a failing crankcase vent valve or valve cover gasket can cause a vacuum leak that affects cylinder 4 more than others, setting this code without any ignition fault.
Swapping coils and plugs is a quick diagnostic step, but technicians often forget to clear adaptations and recheck misfire counters after the repair, leading to a false return of the code.
A flashing check engine light with P1349 means the misfire is actively damaging the catalytic converter, so driving even short distances can be expensive.
Low fuel pressure or a restricted fuel filter can cause a lean misfire that affects cylinder 4 first on some BMW engines, so always verify fuel pressure before replacing ignition parts.

Can I keep driving with P1349?

Do not continue driving with an active P1349, especially if the check engine light is flashing, because unburned fuel can overheat and destroy the catalytic converter. If you must move the car, drive at low speed and light throttle directly to a repair shop, and avoid sustained highway speeds or heavy acceleration.

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 BMW vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.