Catch Can

Why I’m removing my HPD Catch Can

Article from 4Wding Australia.

Fitting a catch can to a modern turbo diesel is extremely important. I wrote a post some time ago, covering this, and mentioning that I installed a catch can from HPD, or High Performance Diesel. You can read more about this here – Is a Catch Can important on a modern turbo diesel?

Many of you know that I am extremely thorough in my research, and like any products I fit to my Dmax, I spend a lot of time researching and weighing up the pro’s and con’s of each option before I lay my hard earned down. I detest buying things twice, and will pay for a quality product the first time over several cheaper units that don’t work as well.

Even well before buying the Dmax, I was doing research into what people recommended, and catch cans were high up there on the list of first modifications you should do to your 4WD. Unless you plan on selling your vehicle after a few years of ownership they are a great idea for longevity.

I read a myriad of forums, commercial posts, sales spiels and comments from owners of MUX and Dmax’s online. The overwhelming majority of people recommended the HPD, with a few people mentioning the Provent 200 as well.

Beyond that though, the HPD unit comes in a complete kit with all the brackets, had a great reputation, was Aussie made and was supposed to work well. There must be thousands of these fitted to various 4WD’s in Australia. They’ve got to be good then, yeah?

Isuzu Dmax Catch Can
The HPD catch can on my Isuzu Dmax

What’s the purpose of a catch can?

The single purpose of a catch can is to filter blow by gasses from the crankcase, and remove as much oil/fuel/water vapour/carbon soot as possible. If you fit a catch can or separator and it doesn’t do this, or it does it poorly then you’ve essentially bought a paper weight.

Beyond this, it needs to separate the fluid without creating a pressure drop. In other words, the air needs to flow into the catch can, through it and out the other side with as little as possible restriction, or this can cause other issues.

Diesel oil catch can pros and cons

Long term, there really is no reason why you shouldn’t install a good quality catch can. It’s the only legal way to keep your vehicles EGR working and your intake manifold clean. This helps maintain good fuel economy, power and ultimately reliability. 

The only con is that they cost money to fit, and there’s a lot of them out there which are poorly engineered and don’t catch much.

Catch can efficiency testing

Not long after writing the post, I received an email with a study from Curtin University, where they tested 12 common catch cans for their ability to catch oil, and you know what? The HPD catch can was the forth worst performer. Consider this a Catch Can Comparison test, with the major brands tested.

To make things worse, it wasn’t even remotely close to the performance of many of its competitors. In terms of a catch can review, the HPD faired very poorly.

HPD vs Provent
Efficiency vs flow rate, with CF2.1 being the Provent 200 and CC1 the HPD

When I first read the report, I was pretty gutted. I’d blown $385 on a HPD catch can and it was barely working. How could I, and so many people get it wrong in recommending the High Performance Diesel catch can?

In the report, the Flashlube catch can pro, Provent 100 and 200 are the best performers by a country mile. I always suspected the Provent’s would filter a lot more than the HPD, but had no proof. If you want to compare the flashlube catch can vs Provent, here’s your answers!

Thinking about it logically, it makes sense. A German engineering company making a catch can with a proper fibrous filter is always going to catch more than a catch can with 4 sets of mesh with an aperture of around 0.5 – 0.8mm on the inlet and outlet. In fact, the results show the Provent catches vapour 5 times more effectively.

In summary though, here’s the catch cans filter quality factor:

  1. Flashlube Catch can (CF 1.2)
  2. Mann and Hummel Provent 200 (CF 2.1)
  3. Mann and Hummel Provent 100 (CF 1.1)
  4. Mann and Hummel Provent 150 (CF 1.5)
  5. Unbranded wire mesh catch can (CF 2.3)
  6. Unbranded fibrous element catch can (CF 1.3)
  7. Unbranded Fibrous element catch can (CF 2.2)
  8. Unbranded wire mesh catch can (CF 1.4)
  9. HPD catch can (CC1)
  10. Taipan wire wool catch can (CC2)
  11. Calibre catch can (CC3)
  12. Mann and Hummel Cyclone with no element (Cyclone)

In terms of pressure drop, capture efficiency and quality factor the Provent 200, and Flashlube take the cake overall.

Catch can comparison
Filter quality comparison between 12 catch cans

Of course, this publication has been put online, and you can read it for yourself here – Catch can study. You will have to sign up to download it, but the report is free. You will get an invoice for $0.00.

In the interest of being completely transparent and sharing everything I’ve learnt, I will mention that the funding for this study at Curtin was provided by Mann and Hummel (the manufacturers of Provent). They paid for a completely independent test to be done, so there would be no conflict of interest.

Provent 100 catch can review
The Provent 100 catch can separator

My independent results

I’ve had the HPD catch can fitted to the Dmax for 27,000km. It was fitted when the Dmax hit 2000km. When I first installed it, the hose clamps supplied by HPD didn’t clamp their new hose onto the OEM barb properly and it did weep a bit of oil out.

I fixed it with proper worm drive hose clamps, and have removed all of the oil recently. It’s caught just 65ml of oil. That’s 24ml of oil for every 10,000km, and is a terrible result. Consider this my HPD catch can review.

EDIT: The Provent wins by a country mile

I ended up running the HPD catch can for 34,000km, then swapped to a Provent 200. I collected the oil caught in both catch cans and meticulously recorded their results. The difference between the two catch cans is chalk and cheese. Check the full post out here; Provent vs HPD Catch Can.

Finding the best catch can was pretty clear cut in this instance!

HPD Catch can inside
The inside of a HPD catch can, with layers of stainless mesh on the inlet and outlet

What does the Provent catch?

By my research, Provent’s fitted to the 4JJ1 motor (same as mine) are collecting 100 – 300ml of oil every 10,000km. That would line up with the 5 x better filtration than the HPD I have experienced!

Obviously, there are a lot of variables at play here – engine oil viscosity and age, engine condition, how the engine is driven and many more. Despite this,  from what I have seen on new 4JJ1 motors (under 50,000km), the Provent catches a LOT more.

Provent separator filter
The Provent separator filter, which is fine fibrous material

Other things to think about

When you buy a catch can, there are other things to consider. Obviously how effective it is at removing vapour is a huge consideration, but  consider these too:

Ease of draining

Before you buy a catch can, look at how they are emptied. The Provent has a drain on the bottom, which most people attach a hose to that comes out near the inner guard. Every so often you get a container under the hose, crack the tap and let it empty.

The HPD catch can has a metal bowl on the bottom which you are supposed to unscrew. There is no chance in the world I can get this undone without removing the catch can. If you have small hands or a filter wrench you can undo it, but the much easier way to empty the can is to suck it out using a big syringe and tube.

Physical size and mounting position

One of the reasons I didn’t get the Provent 200 to start with was their physical size, and where they mounted in off the shelf kits for the Dmax. The only custom Dmax catch can kit that was sold for my model put the catch can where our secondary fuel filter had to go, which created a problem.

If you put dual batteries in your Dmax or MUX you have an even bigger problem, as the Provent, secondary fuel filter and battery all need the same space, so what do you pick?

Of course, I’m more than able to knock up brackets to mount it elsewhere, but the Provent 200’s are seriously big and finding somewhere under the engine bay near the crankcase outlet that isn’t going to interfere with anything else is a mission in itself.

Cost of changing filters

The Provent’s have separators (fibrous filters) that need replacing. The recommendation is somewhere between 40,000 – 75,000km. They are about $80 a pop. The HPD has no filters, and therefore no ongoing costs.

You’ll find this is the biggest grudge that people hold who own Provents, but if you take a step back and actually weigh up how much it adds to your overall maintenance bill, its not much. Lets say you replace it every 50k; its $1.6 every one thousand kilometres.

Some people cheap out and install mesh filters into their Provents, or buy the cheap copies. If you do the first, you’ll lose most of its filtering ability, and the latter can result other issues you really don’t want to deal with, like blown rear main seals. 

Pressure on the motor

You don’t want to put any back pressure on your motor. This is done by fitting catch cans that don’t allow enough air flow through them, or allowing them to fill up and block up. Hoses (or inlets/outlets) that are smaller than the factory ones are a sure way to identify a catch can not suited to your motor. The Provents are sized based on recommended industrial engine CC’s, at high load.

I have spoken to Mann and Hummel, who tell me the Provent 100 is more than suitable for a standard 4JJ1 motor. That said, if you can fit a Provent 150 or 200 it is a better option in terms of offering longer separator/filter/element life.

I would suggest if you have substantially more power and torque than stock, or you work the motor hard (towing something heavy for example) get the Provent 150 or 200.

Provent catch cans come with a relief valve that opens if the pressure builds up too much. HPD have nothing like this, but because the filters are much less fine the chances of back pressure is substantially less. There is a chance of the dipstick on the HPD popping out under pressure, as long as the hose outlets aren’t over the top of it.

I don’t know what sort of pressure you’d need to do this though, as they are quite tight around the 0 ring.

Provent 200 review
The Provent 200. All of their units have in built pressure relief valves

Quality of construction

The HPD kit is well made, there’s no doubting that. However, they do lack in some areas:

  • The bracket holding the catch can up rubs on the brake lines unless you bend them over. This could have easily been rectified in the design phase (or at least mentioned in the instructions). I simply bent the brake line a tiny bit.
  • The air intake hose clamp (under the catch can) rubs on the catch can unless you rotate it, which is not mentioned in the fitting instructions.
  • The plate on the bottom of the bracket to make it sit level is not exactly the right thickness (out by around 0.5mm on my vehicle), which puts extra stress on the panels. I have seen a photo of someone’s cracked inner guard where the catch can bracket bolts to. I suspect it is due to the uneven surface, but also because the bracket can move back and forth over corrugations. A lot of people report vibrations/noises coming from the inner guard after fitting a HPD catch can, and I concur with this. Even though they are aluminium, they are still a heavy unit.
  • The hose clamps that came with the catch can was not suitable for the hose they provided. You could easily pull the hose off the crankcase hosetail even with their clamp on, and this meant that oil would weep out as well, all over the side of your motor. I put up with it for a while, but eventually changed the clamps to worm drive ones and it never leaked again.
  • The kit that suits 2012 to 2016 Dmax’s creates a nasty vibration occasionally on take off. I have verified this with my own vehicle, and another one. Remove the catch can from HPD and it goes away. Obviously something isn’t quite right with the kit.

I can’t comment on the quality of the Provent as I’ve never had one, but they are one of the most common catch cans world wide across everything from light vehicles to heavy machinery.

Where to from here?

I’m not really sure. I feel pretty bummed to be let down by the HPD catch can given how it was marketed to me, but I’m going to remove it and try something else.

I was specifically told that these catch nearly as much as the Provents, which obviously is false. In my opinion removing as much oil from the intake is critical on vehicles that run an EGR system, and I want to change it to something else that is going to catch as much as possible.

Ryco have just released a catch can (although I hear its actually bigger than the Provent 200!), and I have heard good things about the Seper8tor as well. I’d like to fit a Provent 200, but will need to spend some serious time trying to see if it will fit, and making up a custom bracket.

EDIT: If you are looking for a Ryco catch can review, there are a few people running them now, and their own website claims they are better than the Provent 200. As far as I know, there has been no independent testing to back this up though.

There is some more testing going on behind the scenes at Curtin University too, which will hopefully result in some more useful information I can pass along.

Update June 2019

A few months ago, Western Filters released a dual mounting bracket, which allowed me to install a Provent 200. The Provent unit goes on one side near the firewall, and the fuel filter (which was in this spot and stopping me from installing a Provent) goes on the other side of the bracket.

With a larger battery its a tight fit, and not the easiest installation, but its done, and now I know I have a quality catch can installed. 

I’ve documented all of the kilometres, and collected all of the oil from the HPD catch can. In due course, I’ll do another write up with the results, and how they compare. In short though, if you look at the catch can filter its pretty obvious which one will catch more oil!

Provent vs HPD Catch can
EDIT: Here’s the results!

Please don’t be upset with the findings

If you own a HPD catch can, I understand you are probably not too happy reading this right now. I’m sorry; I really am. I feel the same way. I write this purely to share what I’ve found. I get no financial incentive either way.

You can agree or disagree with what I’ve written; that’s your call. This is just my findings, and the research laid out for you to read. Do me a favour though, and leave a comment below with what catch can you run, and how much oil it catches.

The HPD Catch can is a decent, Australian made product that works, just not nearly as well as some of its competitors.

What catch can do you run? Are you happy with it?

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Comments 21

  1. Glad I fitted a Provent 200 to my hilux. I did look at the HPD though. It’s worked well since I fitted it, with homemade bracket, no problems at all. Easy to service/clean

  2. 100% agree, I’ve never been a fan of the HPD, I think people like the shiny prettiness, because they do very little else! Drained many catch cans at work as a mechanic and HPD never catch much, and why would they with the course mesh they have, a sock would catch more!

  3. A very honest appraisal. I’m yet to fit a catch can as I still have concerns about dry grit being fed back through the engine with no lubrication.

  4. I ran a provent catch can
    First on my mn triton after paying big $$$$$$$ to clean inlets.
    Put on the provent catch can all good.
    Bought new mr triton first thing i did a provent catch can at 1600km
    Draining about 50 mm of oil very 5000kms i think you cant go wrong.
    Best and easy investment to protect your motor. I also put Moreys diesel stop smoke it keeps your fuel system clean and lubricated

  5. Firstly a request: could you guys please put a name to your articles – all it says is “4Wding Australia” Doesn’t the author deserve some credit?

    Anyway, 2 years ago I purchased a Western Filters kit – fuel filter and Provent 200 – excellent kit, brackets, instructions etc. for my Pajero. It collects quite a bit of oil and surprisingly, 10 – 15% of something that looks like water. I’m glad that muck doesn’t go back into the engine (via the intercooler and inlet system). Cost a total of $620 for the full kit which I think was good value and even a knuckle-head like me could fit it.

  6. My view on it is “I don’t understand why” if this is such a big problem, why wouldn’t every, I’m saying every vehical manufacturer in the world who are installing these modern engineered engines not install Catch Cans to their vehicles straight out of the factory to prevent this happening.
    If it’s a problem, it’s a manufacturing problem i.e. warranty claims etc that they would be concerned with I would have thought.

  7. I worked for Taipan XP { No 10 on the comparison list }, @ 5 years then the company went bust. I was the CNC PROGRAMMER & OPERATOR for the exhaust systems. I also worked in dispatch which included assembling the taipan catch can.
    My trade is fitting and machining .
    The Taipan catch can was machined well, but, I thought, the stainless steel wire wool {gauze} and design of the catch can was poor quality, and your test is prove. No 10. THAT IS WHY : when I brought my new 2018 MU-X; I purchased the PROVENT 200 catch can.
    I believe in my choice that much, I also purchased the PROVENT 200 catch can for my son’s 2013 Hilux, that replaced the inferior taipan catch can.

  8. Have a Ryco RCC350 Catch Can on a Prado 150 3.0lt for nearly 2 years & it consistently removes plenty of sludge when checked every 10k. There is a new version RCC351 which is for Diesel & Petrol engines where the RCC350 was for diesel only.
    From your article you note that the Ryco is possibly larger than the Provent 200. The Ryco is smaller in diameter which allows for easier fitment in tight areas but it is taller, this is the reason I fitted the Ryco to the Prado.
    If interested youtube video for the installation on the Prado at

      1. I have a small cable tie on the can to stop it moving. To clean cut cable tie pull catch can up as it does not screw to bracket, only slips on, then open drain into small container. Once empty drop it back on bracket & new cable tie. Only takes 5 min.
        The kit comes with a drain hose & valve for fitting under vehicle but did not fit it. The reservoir in the can is quite large so doesn’t need the extra hose for storage.

  9. I have a mate who fitted a HPD catch can and blew a rear main engine seal.
    i can’t wait to show him this report, he should send the bill to HPD

  10. The same Curtin University report will tell you that a Provent 100 has a more than adequate flow rate even for a V8 Landcruiser. Time between filter changes is really the only benefit of the the 200 as far as I can see.

  11. I run a Net 4×4 Provent 200 (Catch Can) and PreLine 150 (Fuel Filter) kit in my v6 Amarok, and it catches an incredible amount of oil and water vapour.

    The guys there have done a terrific job of designing their mounting bracket, and it looks like it belongs in the engine bay, to the point that I have had a VW service manager ask if it’s an optional factory accessory

    I looked at the other options on the market, and this was the only one that was never going to mount where it was in the way for when my Amarok is serviced.

    When I looked into Net 4×4, they are the company who worked on Pat Callinan’s Ultimate V6 Amarok, and did all of the suspension and GVM upgrades, and made it ready to be the awesome touring vehicle he built, and the owner is a lovelyand very knowledgeable bloke to talk to on the phone when you need to do stuff to your Amarok – I am a retired mechanic, and very glad I discovered Net 4×4 for accessories for my Amarok, as they are miles above everyone else

  12. Ok so I get a catch can for my new rig. My first question is why aren’t manufacturers putting these on new vehicles? Also do I void any warranty on the vehicle installing one?

  13. My LC200 was fitted with a taipan catch can when I bought it (100,000klms) and I tried to drain it after the last service 120,000 klms. Only drained a minor amount so I removed it completely. the thing was chock a bloke with grey gunky oil. Cleaned it out and put in a new filter. Haven’t drained it again as have only done 5,000 klms, but will be changing to a Provent in the near future.

  14. I too are not happy 😆 (HPD) l was sucked in by the Australia made the beautiful machined shiny surfaces.When it didn’t collect much oil I thought I must have a clean engine. Back to the drawing board. I can’t help being a little suspicious when the study was funded by Provent !

  15. I found exactly the same with the HPD that I put on my Patrol. I saw the same comparison report and subsequently changed to Provent, a world of difference. The HPD being aussie made was my first choice and it was very disappointing given the cost even though it looked the business. Just goes to show you don’t always get what you pay for.

  16. I too fitted a hpd catch can to my 07 rodeo 4jj1, removed it after 18 months and fitted a provent 200 with custom made bracket as I have a fuel pre filter where the provent 200 was supposed to be fitted.
    Provent 200 catches a lot more oil and hpd filter still let some oil and water into the intake.

  17. After a lot research, I purchased my first Provent 200 a few years ago for my MN Triton, and I also bought one for my GU Patrol as soon as got it about 2 years ago. The Provent 200 performs really well and I like the fact it has a pressure relief valve fitted to prevent any build up of pressure in the engine.
    I know a mechanic who installs the ‘shiny’ catch cans to customer vehicles because that what they request, although I’ve told him they don’t perform anywhere near as well as a Provent 200.

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