PETKIT Pura Max 2 wasting litter or leaving residue behind
- Clean litter in the waste bin: the bin fills in days instead of two weeks, and you are topping the drum up far more often than you expected.
- Crumbs left behind after the cycle: the cylinder finishes, but a patch of broken clump and damp granules is still sitting in the litter bed.
- Both at once: the machine seems to remove the wrong things in both directions — it keeps what it should dump and dumps what it should keep.
- Check which sifter is fitted: the Pura Max 2 ships with two. The standard one (P99022) is for tofu and mixed litter; the honeycomb fine one (P99023) is for mineral, clay and bentonite.
- Swap it if it does not match your litter: the spare sits in the accessory pack inside the waste bin compartment, so most owners already own the part they need.
- Re-seat it properly: a correctly fitted sifter can be shaken back and forth in the drum. One that sits rigid, or leaves a visible gap along the edge, is not in its grooves.
- Then fix the litter itself: nothing longer than 12 mm or thicker than 3 mm, fast-clumping rather than slow-clumping, filled below the MAX line, then run Level Cat Litter.
Why one part causes both problems
The Pura Max 2 does not scoop. Its cylinder rotates and the entire litter bed passes over one flat panel, the litter sifter. Anything small enough falls back into the drum; anything larger rides over the edge and drops into the waste bin. That single mesh decides what stays and what goes — which is why "it throws away good litter" and "it leaves residue behind" are usually the same fault seen from two sides.
The mesh is too fine for your litter
Fit the honeycomb fine sifter (P99023) under tofu pellets or a mixed litter and the clean granules are simply too big to fall back through. They travel over the edge with the clumps. The waste bin fills in a few days, the litter level warning arrives constantly, and the running cost of the box goes up rather than down.
The mesh is too coarse for your litter
Fit the standard sifter (P99022) under fine bentonite or clay and a soft or freshly formed clump does not survive the trip. It breaks apart on the mesh and drops back into the drum as crumbs and damp granules — the residue you find sitting in the litter bed once the cycle has finished. Nothing is broken; the clump just never made it to the bin in one piece.
Two more things push the same system over the edge: a bed filled above the MAX line, and slow-clumping litter that has not set hard by the time the cylinder turns. The steps below work through all four in about 20 minutes.
Fix it step by step
Work in order. Part A settles which sifter you should be running; Part B fixes the litter and the settings around it. Tick each step off as you go.
Lost the spare sifter, or bent the one you have?
PETKIT sells the magnetic litter remover and sifter set for the Pura Max 2 and Purobot Max Pro, which includes both mesh types.
If the issue persists: replacement options
Two parts wear out on this system and both produce the symptoms above. The litter sifter has to be bent every time it is fitted, so after a year or two of cleaning cycles it can hold a permanent curve and stop sealing against the drum. The high-performance cat litter pad is the other one — PETKIT says to replace it when litter sticks to it severely or when it is broken, and a pad that litter clings to leaves a damp patch behind on every cycle no matter which mesh you run.
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The litter pad linked above is the Pura Max 2 / Purobot Max Pro size — the Pura Max Gen 1 pad is a different part and will not fit. If you are still choosing between litter families, the section below lays out what each one asks of the machine.
Litter choice and edge cases
The Pura Max 2 works with most clumping litters, but each family puts a different demand on the sifting system. Here is how to read that, and what to check when the swap alone does not settle things.
Which litter family needs which sifter
Tofu litter and mixed litters are made of relatively large granules, so they need the wide openings of the standard sifter to fall back through. Bentonite, clay and other mineral litters are much finer and form denser clumps; they need the honeycomb fine sifter, which keeps the clump intact on its way to the bin instead of letting it break up and drain back.
Mixed litters — a tofu base with bentonite blended in — are the awkward case, because the two components want different meshes. PETKIT classes them with the large particles and points you at the standard sifter. If you run a mixed bag and still lose fine material into the bin, that is the trade-off you are making, and a single-family litter will behave more predictably.
Whatever you buy, the size ceiling applies across all of them: nothing longer than 12 mm or thicker than 3 mm. Crystal and silica litters are a separate matter — they are non-clumping, and PETKIT builds a different machine for those.
You changed the sifter and crumbs still appear
Look at the cat litter pad rather than the mesh. If litter is sticking to the pad, the material never reaches the sifter in the first place — it stays glued to the drum wall and you find it as a smear once the cycle ends. PETKIT's cleaning table calls for wiping the pad with a soft cloth or paper towel and clean water, without scrubbing, and replacing it when litter sticks to it severely or it is broken.
What you must not do is try to restore it with alcohol, disinfectant, bleach or any non-neutral detergent. PETKIT prohibits all of those on the coated parts, and they strip the water-repellent finish that makes the pad non-stick in the first place — turning an occasional smear into a permanent one.
Check the pad is refitted correctly too: insert the top of it into the groove, then the bottom, align the arrows at both ends, and confirm the green edge is no longer visible. If you can still see green, it is not seated, and litter will work its way underneath it.
| Litter family | Sifter to fit | Symptom if you get it wrong |
|---|---|---|
| Tofu | Standard — P99022 | Clean pellets dumped into the waste bin |
| Mixed (tofu + mineral) | Standard — P99022 | Clean pellets dumped into the waste bin |
| Bentonite | Honeycomb fine — P99023 | Clumps break up, crumbs left in the bed |
| Clay / mineral | Honeycomb fine — P99023 | Clumps break up, crumbs left in the bed |
| Any family, particles > 12 mm or > 3 mm thick | Outside PETKIT's spec | Neither sifter sorts it reliably |
Frequently asked questions
Why is my PETKIT Pura Max 2 throwing away clean litter?
Almost always because the fitted sifter has openings too small for the litter you are using. The honeycomb fine sifter (P99023) is meant for bentonite, clay and mineral litter; put tofu or mixed litter over it and the clean granules cannot fall back into the drum, so they ride over into the waste bin with the clumps. Fit the standard sifter (P99022) instead — it ships in the box.
Why does my Pura Max 2 leave litter in the middle after a cycle?
The opposite mismatch. With the wide-opening standard sifter under fine bentonite or clay, a soft or freshly formed clump breaks apart as it crosses the mesh and falls back into the bed as crumbs. Fit the honeycomb fine sifter, switch to a fast-clumping litter, and enable Waste Covering Mode so clumps have set before the cylinder turns.
Does the Pura Max 2 detect what kind of litter I am using?
No. Its 11 sensors are weight sensors in the base and proximity sensors for cat detection — they exist for safety and for tracking your cat, not for analysing the litter. The machine has no way to know what you poured in, which is exactly why choosing the correct sifter yourself is the whole fix.
Do I have to use PETKIT's own litter in the Pura Max 2?
No. PETKIT states the box works with most clumping cat litters, provided the particles stay under 12 mm long and 3 mm in diameter and you fit the matching sifter. Fast, tight-clumping litter performs better than slow-clumping litter in this machine, but the brand is your choice.
How often should I replace the litter sifter?
There is no fixed interval. PETKIT's guidance is to replace it when it is bent or damaged. Since fitting it involves bending it each time, check it whenever you deep-clean: if it no longer lies flat on a table, or if it cannot be shaken back and forth once installed, it has lost its shape and should be replaced.
Conclusion
If your Pura Max 2 is both hoarding what it should dump and dumping what it should keep, you are looking at one part doing one job badly — and the spare you need is very often still in the box it arrived in. Match the mesh to your litter, check it rattles once fitted, keep the bed below the MAX line, and give the clumps time to set. Tell us which litter you run and which sifter was fitted when you opened it up; that pairing is the single most useful detail for anyone else reading this.
The complete PETKIT Pura Max 2 bulletin library
Every PETKIT Pura Max 2 bulletin published on the site, in one place:
| Bulletin | Covers |
|---|---|
| TB-PPM-001 | PETKIT Pura Max screen not working — blank, black, or unresponsive OLED display? Start… |
| TB-PPM-004 | PETKIT Pura Max leaking odor from a gap between the waste drawer lid and the bin rim?… |
| TB-PPM-005 | PETKIT Pura Max or Pura Max 2 still smelling after a full clean? Urine pooling under… |
| TB-PPM-006 | PETKIT Pura Max 2 stuck on a safety pause or showing inaccurate weights? Learn to… |
| TB-PPM-008 | PETKIT Pura Max 2 air purifier batteries dying within a week? It's not the battery… |