All Codes/P0303

Code P0303Immediate

Cylinder 3 Misfire Detected

Cylinder #3 is misfiring - like having a runner with a injured leg, the engine struggles and shakes.

Professional Service
Available
Category
ignition
Common In
Audi A4

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Immediate Action Required

This issue can cause significant damage if ignored. Stop driving if experiencing severe symptoms.

Recommended Actions:

  • Pull over safely if engine is misfiring badly
  • Call for professional diagnosis immediately
  • Do not ignore flashing check engine light
  • Avoid highway driving until repaired

What This Code Means

The #3 cylinder is not firing properly, causing engine performance issues.

"Cylinder #3 is misfiring - like having a runner with a injured leg, the engine struggles and shakes."

Common Causes

1

Worn spark plug cylinder 3

2

Defective ignition coil cylinder 3

3

Clogged fuel injector cylinder 3

4

Low compression cylinder 3

5

Carbon buildup on valves

Symptoms You May Notice

Engine vibration
Hesitation during acceleration
Rough idle
Decreased fuel efficiency
Possible engine knock

Professional Diagnostic Steps

Our technicians will perform these checks:

Replace spark plug cylinder 3
Test ignition coil resistance
Clean or replace fuel injector
Check valve adjustment

Commonly Affects These Vehicles

Audi A4
BMW X3
Chrysler 300
Dodge Charger
Infiniti Q50

Note: This code can appear in any vehicle. These are just the most common.

Repair Cost Breakdown

DiagnosisAvailable
Often waived with repair
PartsQuality Options
OEM or quality aftermarket
LaborProfessional Service
Professional installation
Total RangeCall for Quote

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  • ASE Certified Technicians
  • Latest Diagnostic Equipment
  • Warranty on All Repairs
  • Upfront, Honest Pricing
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Frequently Asked Questions About Code P0303

Can I keep driving with code P0303?

Minimize driving - misfires can cause $2000+ catalytic converter damage

How much will it cost to fix P0303?

The repair approach depends on the specific cause and your vehicle.The most common cause (worn spark plug cylinder 3) usually costs on the lower end of this range.

Will code P0303 clear itself?

While the check engine light may turn off if the condition improves temporarily, the code will remain stored in your vehicle's computer. The underlying issue still needs to be addressed to prevent the code from returning and potentially causing damage.

Is P0303 covered under warranty?

Coverage depends on your vehicle's warranty status and the specific component that failed. Extended warranties may cover this repair.

Don't Guess - Get Professional Diagnosis

Code P0303 can have multiple causes. Our diagnostic process ensures we fix the right problem the first time.