P0303 Code: 2022 Buick Enclave – What It Means & Cost to Fix

2022 Buick Enclave P0303 Code: Cylinder 3 Misfire Diagnosis

A P0303 diagnostic code on your 2022 Buick Enclave indicates the engine control module has detected repeated misfires in cylinder 3. The full-size luxury SUV uses GM's proven 3.6L V6 engine.

3.6L V6 Engine Layout

The 2022 Enclave uses the LGX 3.6L V6 producing 310 horsepower. Cylinder 3 is located on the driver's side (left) bank at the rear position. This transverse-mounted engine has good access to most ignition components.

Common Causes

  • Ignition Coil Failure: Individual coil-on-plug units can fail
  • Spark Plug Wear: GM's iridium plugs eventually need replacement
  • Fuel Injector Problems: Direct injection deposits or failures
  • Carbon Buildup: GDI technology leads to intake valve deposits
  • Intake Manifold Leaks: Gasket or vacuum line failures

Diagnostic Approach

Use a GM-compatible scanner for detailed diagnostics. Monitor misfire counts and fuel trim data. Test ignition components through swap testing. Check for known V6 issues like carbon buildup.

Repair Solutions

Replace failed ignition coils with AC Delco components. Install GM-specified iridium spark plugs. Clean or replace fuel injectors as needed. Consider carbon cleaning for higher mileage vehicles.

Parts & Tools for This Case

Based on our investigation, these parts may be needed for this repair.

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