Description
A3231C Heavy-Duty Air Filter for 2017-2019 Duramax L5P 6.6L
The iFJF A3231C Engine Air Filter is purpose-built for the most powerful Duramax ever made — the 2017-2019 6.6L L5P turbo diesel V8 producing 445 horsepower and 910 lb-ft of torque. This engine demands an air filter that can flow massive volumes of clean air without restriction — especially when towing at highway speeds or climbing grades under load. This direct OEM-replacement filter delivers exactly that.
The L5P's variable-geometry turbocharger (VGT) is a precision component with turbine blades spinning at over 100,000 RPM. A single grain of sand passing through a cheap air filter can erode the compressor wheel — causing imbalance, reduced boost, and eventual turbo failure. The A3231C's multi-layer synthetic-blend media ensures only clean air reaches your turbo.
Key Features
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L5P-Specific Design: Engineered specifically for the 2017-2019 Duramax L5P airbox — not a universal filter adapted to fit. Matches the factory filter's dimensions, seal profile, and airflow characteristics precisely
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OEM Direct Replacement: Replaces GM part number 84262965 and ACDelco A3231C
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Maximum Airflow: Ultra-high-capacity pleated media designed for the L5P's class-leading 445hp/910lb-ft output — zero restriction at full throttle under load
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Towing-Ready Durability: Reinforced filter construction prevents collapse during sustained high-load operation — essential for towing heavy trailers at highway speeds
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Advanced Filtration: Multi-layer synthetic-blend media captures fine particulates that can damage the L5P's precision VGT turbocharger
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45,000-Mile Service Life: Recommended replacement interval under normal highway/towing conditions
Vehicle Compatibility
| Make |
Model |
Engine |
Years |
| Chevrolet |
Silverado 2500HD |
6.6L Duramax L5P V8 Turbo Diesel |
2017-2019 |
| Chevrolet |
Silverado 3500HD |
6.6L Duramax L5P V8 Turbo Diesel |
2017-2019 |
| GMC |
Sierra 2500HD |
6.6L Duramax L5P V8 Turbo Diesel |
2017-2019 |
| GMC |
Sierra 3500HD |
6.6L Duramax L5P V8 Turbo Diesel |
2017-2019 |
FAQ
Q: Will this fit my 2018 L5P?
A: Yes — designed specifically for 2017-2019 Silverado/Sierra 2500HD and 3500HD with the 6.6L Duramax L5P diesel engine. Matches the factory filter box dimensions and seal perfectly.
Q: How often should I replace the air filter on my L5P?
A: GM recommends replacement at 45,000 miles under normal conditions. If you drive on dirt/gravel roads, tow frequently, or live in dusty environments (desert southwest, agricultural areas), inspect every 15,000 miles and replace by 22,500 miles. A dirty air filter on a turbo diesel reduces boost pressure, increases EGTs, and kills fuel economy.
Q: Is this a washable/reusable filter like K&N?
A: No — this is a traditional dry media filter, not an oiled cotton gauze filter. Dry filters are recommended for the L5P because (1) they don't risk oil contamination of the MAF sensor, and (2) they provide more consistent filtration throughout their service life without the cleaning/re-oiling maintenance cycle that oiled filters require.
Q: Can I use this on a 2020+ L5P?
A: The 2020+ Silverado/Sierra HD uses a different airbox design. This filter is specifically for 2017-2019 model years. Check your owner's manual for the correct part number for 2020+ models.
Q: What are signs my Duramax air filter needs replacement?
A: Watch for: (1) Reduced fuel economy — a clogged air filter richens the air-fuel mixture; (2) Black smoke under acceleration — incomplete combustion from restricted airflow; (3) Lower boost pressure on your gauge if equipped; (4) Visual inspection — hold the filter up to sunlight; if you can't see light through the media, it's time to replace.
Q: Does a performance air filter increase horsepower?
A: On a stock L5P, the factory airbox and filter flow more than enough air for the 445hp rating. A clean, high-quality OEM-spec filter like the A3231C maintains that flow — but don't expect horsepower gains from the filter alone. For significant airflow increases, a complete aftermarket intake system is required.
Q: How do I find the right air filter for my Duramax by part number?
A: Search by the exact part number printed on your existing filter: A3231C (ACDelco number) or 84262965 (GM OEM number). These are the two most common search terms Duramax L5P owners use. The A3231C is specifically for 2017-2019 L5P engines — 2020+ models use a different airbox and filter design. Always match the number on your old filter to ensure correct fitment.
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