Nissan Check Engine Code
P0300 on Nissan
Random / Multiple Cylinder Misfire Detected
Also covers: Infiniti
P0300 on Nissan: what makes it different
P0300 (random/multiple cylinder misfire) is a very common concern on Nissan vehicles, especially those equipped with the VQ35DE V6 and QR25DE four-cylinder engines. Both platforms have known ignition and fuel-delivery characteristics that make them prone to misfire codes, and the VQ-series in particular develops misfires from coil-on-plug failures that are straightforward to diagnose.
Most-affected engines
- VQ35DE 3.5L V6 (Altima, Maxima, Murano, Pathfinder, 350Z)
- QR25DE 2.5L I4 (Altima, Sentra, X-Trail)
- KA24DE 2.4L I4 (older Frontier, Xterra)
Common model years: 2002–2018
Most likely cause on Nissan
Failed or weakened coil-on-plug ignition coil(s) on the VQ35DE V6, which are sensitive to heat cycling and commonly fail between 60,000 and 120,000 miles.
Known Nissan engine-family issues
The VQ35DE's rear cylinder bank (cylinders 4–6) runs significantly hotter than the front bank due to its position near the firewall with less airflow. As a result, coil-on-plug units on the rear bank tend to fail first and more frequently. It is common practice to replace all six coils at once when any one fails, since the remaining rear-bank coils are likely near the end of their service life. The QR25DE in 2002–2006 Altimas also has a documented history of intake manifold gasket leaks that create lean-misfire conditions mimicking ignition failure.
Nissan-specific causes (most common first)
- Individual coil-on-plug failure on VQ35DE or QR25DE — coils degrade from heat and vibration and produce intermittent misfires that can appear random across cylinders
- Spark plug fouling or electrode wear — Nissan recommends longer change intervals than many owners follow, and worn plugs amplify weak-coil misfires
- Fuel injector clogging or weak injector pulse on QR25DE, causing lean misfire under load
- Crankshaft or camshaft position sensor signal dropout triggering false random misfire codes, especially on higher-mileage VQ engines
- Intake manifold gasket seeping on QR25DE, causing lean conditions that trigger misfires at idle
- Low engine compression from timing chain stretch or valve wear on high-mileage VQ35DE engines
Nissan-specific diagnostic tip
On a VQ35DE with P0300 plus any single-cylinder companion code (P0301–P0306), swap the suspect coil to a known-good cylinder and clear codes. If the misfire follows the coil to its new cylinder, the coil is confirmed bad. If the misfire stays in the original cylinder, suspect the spark plug or injector. This swap test is especially easy on the front bank (cylinders 1–3) without special tools, and avoids spending money on a full coil set before confirming the diagnosis.
Symptoms drivers report
- Check engine light (often flashing — flashing means catalytic damage is happening now)
- Rough idle, shuddering
- Loss of power
- Hesitation or stumble under load
- Smell of unburned fuel
Typical repair cost on Nissan
Most Nissan owners fix P0300 for between $80 and $650, depending on which underlying cause turns out to be at fault. Start with the most-likely cause for your vehicle — Failed or weakened coil-on-plug ignition coil(s) on the VQ35DE V6, which are sensitive to heat cycling and commonly fail between 60,000 and 120,000 miles. — before throwing parts at it.
Nissan P0300 FAQ
How do I know if my Nissan VQ35DE misfire is a coil or a spark plug?
Perform the coil-swap test: move the coil from the misfiring cylinder to a healthy cylinder and rescan. If the misfire code follows the coil, replace the coil. If the misfire stays in the original cylinder, swap the spark plug next. Given the VQ35DE's heat environment on the rear bank, both the coil and plug are often worn together, so replacing both at the same time is cost-effective.
My Nissan Altima P0300 only appears at idle — what does that suggest?
A misfire only at idle on the QR25DE Altima often points to an intake manifold gasket leak or a dirty/failing idle air control system rather than pure ignition failure. Spray a small amount of carburetor cleaner around the intake manifold base at idle — if the engine RPM changes, you've likely found a vacuum/gasket leak. Confirm with a smoke test before replacing ignition components.
Can a bad crankshaft position sensor cause P0300 on a Nissan?
Yes. The crankshaft position sensor (CKP) on higher-mileage VQ and QR engines can develop erratic signal output, which the ECM interprets as misfires occurring across multiple cylinders — hence the random P0300 rather than a single-cylinder code. If coils and plugs check out, monitor CKP sensor signal waveform with an oscilloscope or advanced scanner to rule this out.
Related codes
Drive a different make? See the general P0300 guide for cross-vehicle causes and symptoms.
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Most common fix for P0300:
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