iFJF A3231C Engine Air Filter — Keep Your Duramax L5P Breathing Clean
Your 6.6L L5P Duramax moves a lot of air — upwards of 900 CFM at full boost. Every cubic foot of that air passes through the engine air filter before it hits the turbocharger. A clogged, cheap, or torn filter doesn't just choke power — it sends abrasive particulate straight into the compressor wheel, through the intercooler, and into your cylinders.
The iFJF A3231C is a direct drop-in replacement for the OEM air filter on 2017–2019 Silverado & Sierra 2500HD/3500HD trucks. High-flow synthetic cellulose media. Precision-molded polyurethane perimeter seal. No tuning required. No fitment drama. Just cleaner air for a harder-working engine.
📊 iFJF A3231C vs. OEM ACDelco Air Filter
Specification
iFJF A3231C
OEM ACDelco A3231C
Filter Media
High-Flow Synthetic Cellulose Blend
Standard Cellulose Paper
Media Layering
Progressive-Density (Gradient)
Single-Density
Pleat Design
Deep-Pleat, High Surface Area
Standard Pleat Count
Perimeter Seal
Molded Polyurethane — No Bypass
Foam / Rubber Gasket
Airflow Restriction
Low-Restriction at Rated CFM
Standard Restriction
Dirt-Holding Capacity
Enhanced — Longer Service Life
Baseline
Price
$29.99
$38–$55
🚛 Compatible Vehicles
Chevrolet Silverado 2500HD / 3500HD
2017 · 2018 · 2019
6.6L L5P Duramax Turbo Diesel V8
GMC Sierra 2500HD / 3500HD
2017 · 2018 · 2019
6.6L L5P Duramax Turbo Diesel V8
⚠️ Fitment Note: Confirmed for 2017–2019 L5P air filter housings only. Some 2020 models use a revised airbox design — verify your housing before ordering. Not compatible with 2011–2016 LML trucks.
🔢 Cross-Reference / Replaces OEM Part Numbers
ACDelco: A3231C
GM Genuine: 84262965
WIX: CA12258
Baldwin: LAF3231
Purolator: 33-5065
⚙️ Technical Specifications
Filter Media: Progressive-density synthetic cellulose blend — coarser outer layer captures larger debris (leaves, insects, gravel dust); finer inner layer traps sub-visible particulate before it reaches the turbocharger
Pleat Geometry: Deep-pleat design maximizes surface area within the OEM airbox footprint — more media area means longer service life and lower restriction at high CFM demand
Perimeter Seal: Molded polyurethane gasket forms a compression seal against the airbox sealing surface. No tape, no foam strips, no adhesive — just a clean mechanical seal that prevents unfiltered air bypass
Airflow Design: Low-restriction media formulation tuned for the L5P's turbocharger demand curve — maintains rated airflow without sacrificing filtration efficiency
Construction: Heavy-gauge expanded metal support mesh on the clean side prevents media collapse under high vacuum (heavy throttle, high altitude, or partially loaded filter conditions)
Service Interval: Inspect every 15,000 miles. Replace at 30,000 miles under normal conditions, or every 15,000 miles if operating in dusty environments (gravel roads, construction sites, agricultural use)
Installation: Drop-in — no modifications, no tuning, no special tools. Open airbox, lift out old filter, drop in A3231C, reclip. Under 2 minutes.
🛠️ Installation — 90-Second Drop-In
OPEN THE AIRBOX: Release the 4 spring clips on the factory air filter housing. Lift the lid enough to access the old filter.
REMOVE OLD FILTER: Pull the old filter straight out. Note which side faces up (the dirty side will be darker).
INSPECT THE AIRBOX: Wipe out any debris, leaves, or sand from the bottom of the airbox with a shop rag. Check that the airbox drain hole isn't plugged.
DROP IN THE A3231C: Seat the filter with the polyurethane gasket facing the clean-air side (toward the intake tube). The gasket compresses when you close the lid — that's your seal.
CLOSE AND CLIP: Press the lid down evenly and re-engage all 4 spring clips. Give it a wiggle — the lid should be tight with no gaps.
❓ FAQ
Q: Will this fit my 2020 Silverado 2500HD L5P?
A: Maybe not. GM revised the air filter housing on some 2020 L5P trucks. The A3231C is confirmed for 2017–2019 model years. Check your existing air filter part number — if it's stamped A3231C or 84262965, this fits. If it's a different number, your truck may use the revised housing. When in doubt, grab our TP1015 fuel filter instead — that fits all 2017–2020 L5Ps.
Q: How often should I replace the air filter?
A: GM recommends inspection at every oil change and replacement at 30,000 miles. In practice, if you tow, drive gravel, or operate in dusty conditions (construction, agriculture, Southwest desert), replace every 15,000 miles. A $30 filter is cheap insurance against a dusted turbo or scored cylinder walls.
Q: Will this air filter give me more horsepower?
A: The A3231C is not a "performance" filter in the oiled-cotton sense — it's an OEM-spec replacement engineered for better filtration at equal or lower restriction. On a dyno, you won't see a horsepower gain. What you will get is cleaner intake air, longer turbo life, and the confidence that your filter media isn't collapsing under high boost. For a true high-flow upgrade on a tuned truck, aftermarket intake systems exist — but for a stock or lightly modified daily driver, this is the filter you want.
Q: Will using an aftermarket air filter void my warranty?
A: No. The Magnuson-Moss Warranty Act protects your right to use aftermarket replacement parts. The iFJF A3231C meets or exceeds GM's filtration and airflow specifications. As long as the filter itself doesn't cause a failure (and it won't — it's a direct dimensional and performance equivalent), your warranty is safe.
🛒 Complete Your L5P Maintenance
Need the fuel filter too? TP1015 + A3231C Air Filter Combo — $37.99, both filters in one order, one shipping charge
Just the fuel filter? TP1015 Fuel Filter — $17.99, 5-micron absolute filtration for your CP4.2 pump
Upgrade your fuel filter cap? Silver 134001 Billet Cap + TP1015 Kit — $69.99, fix the brittle OEM plastic cap permanently
💡 TIP: A dirty air filter doesn't just hurt performance — it increases fuel consumption. A restricted filter forces the turbo to work harder to pull air, which the ECM compensates for with more fuel. Keep your A3231C clean, and your Duramax will return better MPG.
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