When your 2022 Nissan Altima starts shaking at idle with a P0300 code lighting up the dashboard, random misfires are disrupting the normally smooth four-cylinder engine. The VC-Turbo and naturally aspirated engines in this generation have different considerations, so identifying your engine helps narrow down the investigation.
Understanding P0300 on the Altima
The P0300 code indicates misfires are occurring across multiple cylinders without a consistent pattern. Unlike cylinder-specific codes (P0301-P0304), random misfires suggest a systemic issue affecting all cylinders—fuel delivery, air supply, or a common ignition component.
Symptoms Beyond the Rough Idle
- Engine shakes or vibrates at stoplights
- Check engine light steady or flashing
- Hesitation during acceleration
- Reduced fuel economy
- Possible smell of unburned fuel
- Engine may stall at idle
Common Causes in the 2022 Altima
- Spark plug fouling: Carbon buildup on plugs causes weak spark
- Ignition coil failure: One or more coils producing inconsistent spark
- Fuel injector issues: Clogged or malfunctioning injectors
- Vacuum leak: Unmetered air entering the intake
- Carbon buildup: Deposits on intake valves (direct injection engines)
- Low fuel pressure: Weak fuel pump or restricted filter
VC-Turbo Specific Considerations
If your Altima has the variable compression turbo engine, additional factors include:
- Turbocharger issues affecting air delivery
- More sensitive to spark plug condition due to higher compression
- Intercooler leaks causing inconsistent charge air
Diagnostic Approach
- Check for additional codes that might indicate specific cylinders
- Inspect spark plugs for wear, fouling, or damage
- Test ignition coils with a scan tool or swap test
- Look for vacuum leaks around the intake manifold
- Check fuel pressure at the rail
Repair Cost Estimates
- Spark plugs (set of 4): $100-$200
- Ignition coil (each): $75-$175
- Fuel injector cleaning: $100-$200
- Vacuum leak repair: $100-$300
- Fuel pump replacement: $400-$800
Your 2022 Altima should still be under Nissan's 3-year/36,000-mile basic warranty, so have the dealer diagnose it first.