When your 2023 Chevrolet Tahoe displays a P0302 code, the powertrain control module has identified a misfire condition in cylinder 2. The 2023 Tahoe offers three engine options: the 5.3L V8 (L84), 6.2L V8 (L87), and the 3.0L Duramax turbo-diesel inline-6 (LM2). Diagnostic approaches vary significantly between these powertrains.
Engine-Specific Considerations
For the V8 engines, cylinder 2 is located on the passenger side and is equipped with Dynamic Fuel Management technology. The 3.0L Duramax uses a different firing order and cylinder arrangement as an inline-6, making cylinder 2 the second from the front. Diesel misfires are typically caused by different issues than gasoline engine misfires.
V8 Misfire Causes
The 5.3L and 6.2L V8 engines share common misfire causes including DFM lifter issues, spark plug degradation, ignition coil failure, and fuel injector problems. The 2023 models use updated DFM lifter designs, but early failures are still possible. Carbon buildup on direct-injection engines can also contribute to misfires.
Duramax Diesel Misfire Causes
The 3.0L Duramax can trigger P0302 due to faulty fuel injectors, low fuel pressure, glow plug problems, or compression loss. Unlike gasoline engines, diesels don't have spark plugs, so diagnosis focuses on fuel delivery and compression. Injector coding issues after service can also cause cylinder-specific misfires.
Diagnostic Steps
Begin with a thorough code scan including freeze frame data. For V8 engines, inspect ignition components and monitor DFM operation. For the Duramax, check fuel pressure, injector balance rates, and glow plug operation. Both engine families benefit from compression testing to rule out mechanical issues.
Repair Options
V8 repairs typically involve spark plug and coil replacement first, followed by DFM lifter service if needed. Duramax repairs may require injector replacement or fuel system service. Both engines should have oil and fuel filters checked, as contamination can contribute to misfire conditions. GM dealer diagnosis is recommended for diesel-specific issues due to specialized equipment requirements.