01 The Underestimated Component That Eats Fuel Faster Than Any… • 02 You Could Destroy Your Entire Engine If You Keep Repeating … • 03 What Speed Do Planes Take Off At? Factors and Examples • 04 B0051: Deployment Commanded • 05 Comprehensive Guide to Diagnosing and Fixing Rough Idle in … • 06 This Maintenance Myth Is Turning Small Car Issues Into Huge… • 07 Clutch Slipping: Symptoms, Causes, and Fixes Explained • 08 How to Avoid and Handle a Hydroplaning Vehicle: A Complete … • 09 Experts Reveal The Real Reason Some Cars Burst Into Flames … • 10 This Easy Sensor Cleaning Trick Fixes Half of Modern Car Is… •

DTC codes / Nissan codes / P1204

P1204 · NissanCylinder 4 Misfire

P1204 on Nissan vehicles indicates that the engine control module has detected a misfire specifically on cylinder number 4, typically by monitoring crankshaft speed fluctuations. The computer sets this code when the misfire rate exceeds a threshold that could damage the catalytic converter or impair emissions.

SystemPowertrain
Code typeNissan specific
SeverityMedium
Fix difficultyIntermediate
AreaFuel and air metering (injector circuits)

Symptoms you may notice

  • Engine may run rough or shake, especially at idle or under light acceleration
  • Noticeable loss of power or hesitation during acceleration
  • Check Engine Light may flash if the misfire is severe enough to risk catalytic converter damage
  • Often no symptoms besides the warning light, especially if the misfire is intermittent
  • Possible poor fuel economy or increased emissions
  • In some cases, a sulfur or rotten egg smell from the exhaust if unburned fuel reaches the converter

Common causes, most likely first

  1. Worn or fouled spark plug in cylinder 4
  2. Faulty ignition coil or coil-on-plug boot for cylinder 4
  3. Leaking or clogged fuel injector for cylinder 4
  4. Vacuum leak affecting cylinder 4 intake runner
  5. Low compression due to worn piston rings, valves, or head gasket
  6. Damaged wiring or connector to the cylinder 4 ignition coil or injector
  7. Mechanical valvetrain issue such as a worn cam lobe or collapsed lifter

How to diagnose and fix it

  1. Perform a visual inspection of cylinder 4 ignition components and wiring for damage or corrosion
  2. Swap the ignition coil from cylinder 4 with another cylinder to see if the misfire moves
  3. Remove and inspect the spark plug from cylinder 4 for wear, fouling, or incorrect gap
  4. Test the fuel injector for cylinder 4 with a noid light or listen for clicking
  5. Run a compression test and a cylinder leak-down test on cylinder 4
  6. Check for vacuum leaks at the intake manifold and cylinder 4 runner
  7. If the misfire persists, perform a crankshaft position variation relearn or inspect the ECM for software updates

What Nissan Technicians Check First for P1204

  • A misfire on only one cylinder often points to an ignition coil or spark plug, but Nissan coils can fail intermittently when hot, so testing them cold may miss the fault.
  • Fuel injector balance tests are more reliable than resistance checks because a partially clogged injector can still show correct resistance.
  • A vacuum leak at the intake manifold gasket near cylinder 4 can cause a lean misfire that mimics a bad injector, so always smoke-test the intake.
  • Low compression on cylinder 4 may not trigger a misfire until the engine is under load, so a compression test should be done both dry and wet.
  • The ECM may set P1204 without illuminating the Check Engine Light if the misfire is not severe enough to exceed the emissions threshold, so always scan for pending codes.

Can I keep driving with P1204?

You can drive the vehicle if the Check Engine Light is steady and the engine runs smoothly, but avoid hard acceleration and towing. If the light flashes or the engine shakes violently, stop driving and have the vehicle towed to prevent catalytic converter damage.

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.

Running on fumes Free guides aren't free to make. Top up the tank. Any amount, one time. Fuel the Garage