Worn or fouled spark plug in cylinder 5; Faulty ignition coil or spark plug wire for cylinder 5; Clogged or failing fuel injector for cylinder 5; Vacuum leak affecting cylinder 5 intake runner; Low compression due to worn piston rings, valves, or head gasket; Faulty variable valve timing solenoid or oil control valve affecting cylinder 5; Engine mechanical issues such as a collapsed lifter or worn camshaft lobe

DTC codes / Honda codes / P1205

P1205 · HondaCylinder 5 Misfire

Q: What does code P1205 mean?

Cylinder 5 Misfire. P1205 is a Honda-specific code indicating that the powertrain control module has detected a misfire on cylinder 5, typically by monitoring crankshaft speed fluctuations. The computer sets this code when the misfire rate exceeds a calibrated threshold that could damage the catalytic converter or affect emissions.

P1205 is a Honda-specific code indicating that the powertrain control module has detected a misfire on cylinder 5, typically by monitoring crankshaft speed fluctuations. The computer sets this code when the misfire rate exceeds a calibrated threshold that could damage the catalytic converter or affect emissions.

SystemPowertrain

Code typeHonda specific

SeverityHigh

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Symptoms you may notice

Illumination of the check engine light, often flashing if the misfire is severe
Noticeable engine vibration or shaking, especially at idle or under light acceleration
Rough running with a loss of power or hesitation during acceleration
A distinct exhaust note that may sound uneven or popping
Reduced fuel economy due to unburned fuel entering the exhaust
Often no symptoms besides the warning light when the misfire is intermittent or mild

Common causes, most likely first

Worn or fouled spark plug in cylinder 5
Faulty ignition coil or spark plug wire for cylinder 5
Clogged or failing fuel injector for cylinder 5
Vacuum leak affecting cylinder 5 intake runner
Low compression due to worn piston rings, valves, or head gasket
Faulty variable valve timing solenoid or oil control valve affecting cylinder 5
Engine mechanical issues such as a collapsed lifter or worn camshaft lobe

How to diagnose and fix it

Perform a visual inspection of cylinder 5 ignition components and wiring for damage or corrosion
Swap the ignition coil from cylinder 5 with a known-good cylinder and see if the misfire moves
Remove and inspect the spark plug from cylinder 5 for wear, fouling, or incorrect gap; replace if necessary
Run a compression test on cylinder 5 and compare with other cylinders to rule out mechanical faults
Test the fuel injector for cylinder 5 for resistance and pulse signal, and clean or replace if faulty
Check for vacuum leaks at the intake manifold and cylinder 5 runner using a smoke machine or carb cleaner
If all above check out, perform a cylinder leak-down test and inspect valve train components for wear

Cylinder 5 misfire: look beyond the ignition coil

A misfire on only one cylinder often points to a localized issue such as a faulty injector or vacuum leak, but Honda engines are known for valve clearance problems that can cause single-cylinder misfires when neglected.
The P1205 code can be set by a marginal ignition coil that tests fine with a simple resistance check but breaks down under load; swapping coils is a more reliable diagnostic step.
Honda's variable valve timing system can cause a single-cylinder misfire if the oil control valve for that cylinder's bank is sticking, so check oil condition and solenoid function.
A flashing check engine light with P1205 indicates a misfire severe enough to damage the catalytic converter; driving with a flashing light can lead to costly repairs beyond the misfire itself.
Sometimes a P1205 is stored due to a loose or damaged connector at the ignition coil or injector, so always inspect the harness before replacing parts.

Can I keep driving with P1205?

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, you can drive cautiously to a repair shop, but avoid heavy acceleration or towing and get it diagnosed promptly.

Tools that help

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