2017-2019 Duramax L5P 4-Filter Kit Buyer’s Guide (TP1015 / PF2232)

The $13 Filter That Almost Cost Me a Fuel System

A few winters ago I watched a guy in a diesel forum swear up and down that the $13 TP1015 knockoff on eBay was “the same filter, just without the GM logo.” He’d been running them for two oil changes, no problems, “so the OEM upcharge is a scam.” Six months later he was back in the same thread, posting a picture of his injector bench-test results — two injectors spraying a fog instead of a clean cone, the tips eroded from water that flash-boiled to steam at rail pressure.

The 2017-2019 L5P doesn’t give you a lot of warning before a fuel problem turns expensive. The high-pressure Denso HP4 pump feeds eight piezo injectors at over 30,000 psi, and there is no second filter downstream to catch what the fuel filter lets through. The TP1015 in the housing under the cab is the only barrier between whatever came out of your tank and a set of injectors that runs several thousand dollars to replace. On this engine, a “cheap” filter isn’t a bargain — it’s a bet with the house, and the house always wins eventually.

Why the 2017-2019 L5P Is a Different Animal

This is the part that trips people up, because “6.6L Duramax” sounds like one truck. It isn’t. GM made a hard break between the 2017-2019 L5P and the 2020+ L5P, and the filters do not carry over.

The oil filter is the sharpest trap. The PF2232 and the PF26 are both spin-on canisters, and they look close enough that a seller can list the wrong one and get away with it — but the PF2232 will not thread onto a 2020+ engine, and a PF26 is the wrong calibration for a 2017-2019. If you’re shopping and the listing says “fits all Duramax 2011-2025,” close the tab. That’s the tell that the seller doesn’t understand the platform, and you’re about to buy a return label instead of a filter.

The engine itself is also different under the hood than its LML predecessor. The 2017-2019 L5P runs a Denso HP4 high-pressure pump — a more robust unit than the Bosch CP4.2 that plagued the LML and the 6.7L Powerstroke — but “more robust” isn’t “waterproof.” The HP4 still spins at rail pressure on a film of diesel, and water or sediment in that fuel is still how you kill piezo injectors that cost several hundred dollars each.

What’s in the Kit — Four Filters, Four Jobs

The value of a four-filter kit is that it closes every filtration gap in one garage session. Here’s what each element is actually doing on a 2017-2019 L5P:

TP1015 fuel filter (cartridge). This lives in a plastic housing on the driver’s-side frame rail, under the cab. It’s a drop-in cartridge — you unscrew the 36mm cap, lift the old element out, and drop the new one in with two fresh O-rings. Its whole job is stripping water and fine sediment before it reaches the HP4 pump. A proper element uses a coalescing media that separates both free and emulsified water; the cheap knockoffs skip that layer, and the water they let through is exactly what erodes injector tips.

PF2232 oil filter (spin-on). This is the last of the “big” Duramax oil filters before GM shrank it to the PF26 in 2020. The PF2232 holds nearly a quart of oil in the can, with a silicone anti-drainback valve rated to hold oil in the gallery overnight so cold starts aren’t dry starts. On a diesel, the oil filter is doing more than catching wear metal — it’s holding soot in suspension so it doesn’t grind the turbo’s journal bearings.

A3231C engine air filter (panel). Deep-pleat panel element with a polyurethane sealing edge that compresses against the airbox lid. The 2017-2019 airbox is the pre-redesign version, so this is a different shape than the 2020+ A3248C. A dirty or restrictive filter on a VGT-turbo engine doesn’t just cost power — the variable-geometry turbo compensates by closing the vanes, which raises exhaust backpressure and EGT, which triggers DPF regen cycles.

CF188 cabin air filter. The one most owners forget exists, and the one that’s been filtering the air you breathe since the truck rolled off the lot. By 30,000 miles a neglected cabin filter is a mat of dust, pollen, and diesel soot. It’s a ten-minute job that most owners put off for three oil changes.

What You Actually Pay: The Real Comparison

Prices checked September 2026 across the channels that actually carry these part numbers.

The honest read: the TruckTok kit isn’t the cheapest way to buy four filters, and it isn’t trying to be. It’s the cheapest way to buy four filters that are actually the right part numbers for a 2017-2019, with the water-separation spec published, in a single box. The eBay white-label route saves you maybe $14 on paper and hands you four unknowns — including a fuel filter with no micron rating, on an engine where that filter is the only thing standing between your tank and a $3,000 injector set.

What to Look For When Buying

1. Is the oil filter actually a PF2232? This is the 2017-2019 L5P’s version of the “wrong year” trap. The PF2232 is a 2001-2019 Duramax filter; the PF26 is 2020+. They do not interchange. A listing that says “PF2232/PF26” in one breath is a red flag.

2. Is the water-separation spec published for the fuel filter? The TP1015’s job is stripping water before it hits the HP4 pump and piezo injectors. Water at rail pressure flash-boils to steam and erodes the injector tips. A kit that won’t state a water-separation efficiency is asking you to take that on faith.

3. Does the air filter fit the 2017-2019 airbox? The A3231C is a different shape than the 2020+ A3248C. The two look similar in photos — panel, deep pleats, polyurethane edge — but the 2017-2019 element will not seat correctly in a 2020+ box and vice versa. Verify the number, not the picture.

4. Are the O-rings and the cabin filter actually in the box? A fuel filter cartridge is useless without fresh O-rings, and a “4-filter kit” that quietly omits the cabin filter is a 3-filter kit at a 4-filter price. Read the contents line, not the headline.

Installation Guide: Four Filters, Step-by-Step Order

Fuel filter (TP1015) — frame rail. The housing sits on the driver’s-side frame rail, just ahead of the fuel tank — but reach it from the passenger side, because the driver’s-side frame beam blocks the way in.

Drain the water through the drain valve first — a T40 Torx plug on the housing (go gently, that plug strips easily — and plenty of owners skip it entirely, since it only bleeds off a little fuel). Then unscrew the 36mm cap, lift the old cartridge out, and use a pick to roll the two old O-rings off before fitting the fresh ones — the large one in the cap groove and the small one on the center pickup tube. Crucial step: lubricate both O-rings with clean diesel fuel. Skipping the small stem O-ring allows unfiltered fuel to bypass directly to the HP4 pump. When you thread the cap back on, use the Mason twist: turn it left until you feel the click, then right — that seats the threads straight so you never cross-thread the plastic housing. Torque it to 25-30 Nm (the cap is stamped 25 + 5 Nm — aim for ~27 Nm / 20 ft-lb) and watch the gap between the cap and the housing close as you hit spec; stop when it does, because it’s plastic and over-tightening cracks it. To prime a 2017-2019, turn the key to RUN without starting and let the lift pump run 20-30 seconds, then off — repeat four to six times until you hear the air clear. Finally, reset the fuel-filter life from the steering-wheel controls: scroll to Fuel Filter Life, press the right arrow to Reset, hold the check button, and after the double beep, shut the truck off and restart it to display 100%.

Oil filter (PF2232) — driver’s side, bottom. Drain the oil first — the drain plug is a 15mm hex, and a 2" extension with a 15mm deep socket reaches it easily (don’t reach for a crescent wrench or channel-locks, they’ll round the bolt head). Torque it to 32 ft-lb on the full-size plug (18.8 ft-lb if yours is the crush-washer style). Pro Tip: When the PF2232 breaks loose, the oil drains straight down onto the driveshaft and yoke. Keep a flexible deflector, paper towels, or a folded piece of sheet metal as a funnel under it before you spin it off — otherwise it slings oil everywhere on the first drive. Spin the old filter off from underneath on the driver’s side — a 93mm 15-flute cap wrench, or a firm hand if it isn’t seized. Fill the new PF2232 about halfway with fresh oil before threading it on, hand-tight plus a quarter turn, and check that the old gasket didn’t stick to the mounting surface — a doubled gasket will dump your oil on the first start. It takes about 10 quarts of 15W-40; run it 10-15 minutes, then check the dipstick and reset the oil-life monitor from the steering-wheel controls.

Engine air filter (A3231C) — airbox. Unplug the MAP sensor first (red tab + press, then pull), then release the airbox lid screws and lift the panel out. Note the orientation before you pull it — the prism-shaped element only goes in one way. Seat the new one flush on all four corners before you button the lid back down.

Cabin air filter (CF188) — behind the glovebox. On most 2017-2019 trucks you’ll need a T15 Torx driver to pull the two screws securing the lower panel, then drop the glovebox assembly. Slide the old filter out, clean any debris out of the housing, and set the new one in with the airflow arrow pointing down. Reinstall the filter door by threading the bottom tabs into their catch first, then press the top to lock.

Five Expensive Mistakes

Mistake #1: Buying a PF26 because “it’s the same Duramax filter.” It isn’t. The PF26 is the 2020+ filter with revised threads and a smaller can. It won’t thread onto a 2017-2019 engine, and forcing it will cross-thread the mount and turn a $15 filter into a $300 repair.

Mistake #2: Assuming the fuel filter is a spin-on. The 2017-2019 L5P moved to a cartridge element in a plastic housing. If you’re expecting to spin the whole can off, you’ll be confused — and if you buy a spin-on that “looks right,” it’s the wrong part entirely.

Mistake #3: Gambling on a no-name kit to save $14. The eBay route saves pocket change on paper, and hands you a fuel filter with no micron or water-separation rating. On an engine where that filter is the only thing protecting eight piezo injectors, that’s not saving money — it’s financing an injector job.

Mistake #4: Reusing the fuel filter O-rings. The cartridge comes with fresh O-rings for a reason. A reused or rolled O-ring is the single most common cause of a post-service fuel leak, and on a high-pressure common-rail system a leak means air in the rail and a no-start or a hard start.

Mistake #5: Skipping the cabin filter for “one more oil change.” It’s the cheapest filter in the kit and the easiest to install, which is exactly why it’s the one that never gets changed. By 30,000 miles you’re breathing whatever the last owner drove through.

Frequently Asked Questions

What’s the difference between the 2017-2019 and 2020+ L5P filters?

The oil filter and air filter both changed. 2017-2019 uses the PF2232 oil filter and the A3231C air filter; 2020+ uses the PF26 and the A3248C. The fuel filter (TP1015) stayed the same across both. The oil filters do not interchange — the PF2232 won’t thread onto a 2020+ engine.

Why do 2017-2019 L5P trucks use a cartridge fuel filter instead of a spin-on?

The cartridge design replaces only the interior element rather than the whole canister, and it allows multi-layer coalescing media that separates water more effectively. It’s a better filter, but it means you need the housing cap tool (36mm) rather than a strap wrench.

Does this kit fit a 2020 Silverado 2500HD?

No. The 2020+ trucks use the PF26 oil filter and the A3248C air filter. This kit’s PF2232 and A3231C are specific to the 2017-2019 models.

How often should I change each filter?

Fuel, engine air, and cabin air filters every 15,000-20,000 miles (10,000-15,000 under severe towing or dusty conditions). The oil filter at every oil change — 7,500 miles normal, 5,000 miles severe.

How do I prime the fuel system after changing the TP1015?

Turn the key to RUN without starting, let the in-tank lift pump run 20-30 seconds, key off, and repeat four to six times until you hear the air clear. Don’t crank until the system is primed.

Is the fuel filter the same as the one on a 2011-2016 LML?

No. The LML (2011-2016) uses a different filter and a Bosch CP4.2 pump. The 2017-2019 L5P uses the TP1015 cartridge and a Denso HP4 pump. Different platform, different part numbers.

What happens if water gets through the fuel filter?

At rail pressure, water flash-boils to steam and erodes the piezo injector tips. The injectors stop atomizing fuel properly, the truck starts to run rough, and eventually you’re replacing injectors at several hundred dollars each. The fuel filter’s water-separation layer is the only defense.

Can I just change the fuel and oil filters and skip the air and cabin?

You can, and plenty of people do — which is exactly why the air and cabin filters are the ones that never get changed. Bundling all four is the only reliable way to actually replace the two you’d otherwise forget.

Is the Denso HP4 pump a weak point like the CP4.2?

No — the Denso HP4 in the 2017-2019 L5P is genuinely more robust than the Bosch CP4.2 that plagued the LML and the 6.7L Powerstroke. But it’s still a high-pressure common-rail pump that spins on a film of diesel, so clean fuel still matters. The filter is cheap insurance against a pump or injector failure that isn’t.

What’s the cheapest safe way to buy all four filters?

Buy a matched four-filter kit with published specs — like this one — rather than piecing together four white-label filters from four eBay sellers. The kit route guarantees the right part numbers for your exact year and gives you the water-separation spec in writing.

Get All Four Filters, in One Box

If your 2017-2019 Duramax has been running on “whatever was on sale” filters, or the cabin filter is still the one it left the factory with, this kit closes the gap. One order puts the TP1015 fuel filter, PF2232 oil filter, A3231C air filter, and CF188 cabin filter in a single box — matched to your exact year, OEM-spec, and ready for one afternoon in the garage.

Get the 2017-2019 Duramax L5P 4-Filter Maintenance Kit

Want to confirm fitment against what other owners are running? A few threads worth reading:

• 2017-2026 6.6L Duramax Fuel Filter — Replaces TP1015
• 2001-2019 6.6L Duramax Oil Filter — Replaces PF2232
• 2017-2019 6.6L Duramax Air Filter — Replaces A3231C / A3257C
• 2014-2019 Silverado/Sierra Cabin Air Filter — Replaces CP809

Legal Disclaimer

This guide is for general informational purposes only and is not a substitute for your vehicle’s factory service manual or the advice of a qualified diesel technician. Always verify the correct part numbers for your specific model year, VIN, and configuration before purchasing or installing filters. Installation of any aftermarket or replacement part is performed at your own risk; the author and retailer assume no liability for damage, injury, or loss arising from the use of this information or the products referenced. Filter change intervals are manufacturer recommendations and should be adjusted for your driving conditions, towing load, and fuel quality.