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Why I’m removing my HPD Catch Can

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.

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.

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.

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.

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 kit that was sold for my model Dmax 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.

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!

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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100 comments… add one
  • moo August 7, 2019, 12:31 PM

    I have just picked up a 2019 LSU D-Max Space Cab.
    I have plans of travelling this great country, and know that outback petrol stations can suffer from water problems in their fuels due to wet season and excessive heat, I was considering a Fuel Manager system.
    would love some feed back.

  • Aaron Schubert August 7, 2019, 6:34 PM

    Hey Moo,

    Nice work. Sounds like a great plan. I wouldn’t go out of the city without a secondary fuel filter. Isuzu get narky if you put one after their filter, so best bet is prior. You can either get a water watch alarm system, or just a pre filter. I run the 30 micron pre filter which is supposed to separate any water prior to making it to the factory Isuzu one. This is the fuel manager 30 micron pre filter kit. I would speak to Western Filters – they know their stuff and sell quality gear (including the fuel manager).

    Some people argue its better to put the filter after the factory one, but it depends on what you want to believe.

    All the best

  • Gary August 15, 2019, 9:20 AM

    I had a HPD fitted around 1000 kms ago (wish I had seen this article prior) to my V6 D40. On checking the dip stick there is around 10 mm on it. So that adds up with the comments on other brands getting 50 ml per 5000 kms. Unless my engine is releasing an exceptional amount of vapor.

  • Aaron Schubert August 15, 2019, 6:09 PM

    Hey Gary,

    I’d be inclined to say its probably releasing a lot more, but at least you are stopping some of it. You’ll never know unless you swap to a Provent. How many km’s on the motor? How long are you going to keep it? Unfortunately only you can decide whether its worth swapping or not.


  • Peter Skinner August 20, 2019, 5:11 PM

    I’ve had the Provent 200 on my 2010 BT50 for 6 years now & 120,000km. It’s never once skipped a beat and works just as well now as it did when I first put it on. As a test I rinsed the filter in parts washer at 40,000km to see if there would be any issues falling apart etc no visible damage done so I ran for another 40,000km before I replaced with a new filter. I will run the same regiment with it from now on. I found out about the Provent 200 through a mechanic friend who works for a bus company, they are running the provents on there entire fleet.

    I still have the BT50 but recently got an Isuzu MUX for the wife. While talking to the Isuzu parts department today, we got onto the subject of catch cans and they actually have a genuine Isuzu catch can made in Japan for the NPR series trucks. The guy said he has sold a few now to other people using them on there Dmax/Mux. Price I was given for the unit was $110 and replacement media type filters (same style as Provent) are around $20 mark.

    Although the Provent has never let me down, it just can’t compete price wise with the genuine Isuzu catch can. Will be ordering the Isuzu one tomorrow and am super keen to see how it performs against the Provent 200.


  • Aaron Schubert August 20, 2019, 6:53 PM

    Hey Peter,

    Good to hear you’ve had a great run from the Provent. Yep, I know a few people who’ve installed the Isuzu truck catch can. I’d be interested to see the inside of it, and how well it performs compared to the Provent. I wonder if Provent might even have something to do with its origins!

    Let me know how it goes

    All the best

  • Jeffrey Graves August 31, 2019, 4:42 PM

    bought one about 14 months ago … was disappointed with it and then started hearing negative comments about it – dont care if it an aussie product built by aussie workers .. i want a better product than this one when i spend over $400. Now i see there may be an issue with the back pressure so it will be coming off asap. Might even mail it back to the makers …what a con!!!!

  • Aaron Schubert August 31, 2019, 8:11 PM

    Hey mate,

    You aren’t being unreasonable; it should perform better than they do. I’m surprised you are having an issue with back pressure though; these should hardly affect the flow rate.

    All the best

  • Iain September 6, 2019, 2:07 AM

    Hi Aaron,
    Yes I agree with your findings, having sold airline filters for many years, the only serious way to catch oil in my opinion is with a foam or fibrous element. The mesh elements in the HPD are really only a basic filter much like a bronze element in your compressor at home.
    In saying that You should not be too concerned, I have been caught twice now because I had one fitted to my Triton at 4000kms by a Diesel workshop in south east Melbourne and at 15000 kms the oil level had barely reached the bottom of the dipstick. Now in my Pajero Sport (with the same engine) again my local mechanic talked me into fitting a HPD unit because he said the Provent one put too much back pressure on the engine. That went on at 3000 kms and at 9000 kms the level is 40mm up the dipstick and needs to be changed. HPD say it should be changed at 25mm on the dipstick. But the real pain is, how do I remove the bowl, there is no room. So I go back to my mechanic who will charge me $100 to do it (that will get expensive every 6000 kms) or I buy some more tools and do it myself.
    I think HPD must do some serious marketing to the mechanical workshops as twice I have been caught now by mechanics who I thought were good, recommending a faulty product just because it is Aussie made. This exercise has cost me near enough to $1000 so far and I have not bought the Provent one yet. I think I will go back to a petrol SUV.


  • Aaron Schubert September 6, 2019, 6:28 PM

    Hey mate,

    The trick to removing the bowl is not to, unless you have lots of room. Just buy a small syringe from eBay for a couple of bucks and suck it out. The HPD catch cans seem to catch a fair bit of oil in some motors, but I have no doubt the Provent’s would do even more. I wonder if all the back pressure talk comes from people who fit fake filters, don’t change them regularly enough, plumb them up backwards or simply don’t drain the oil enough.

    I think my next vehicle might be Petrol too; diesels are just becoming too complicated


  • Eamon September 28, 2019, 4:05 PM

    After a lot of research on the web I fitted a Provent 200 to my 200 series supplied by Western Filters. Car had 100k km on it which was just after I purchased it. Fitted the catch can before I drove it. Done approx 2,500km so far, mostly trips to Kalbarri from Perth. Drained approx 15-25ml from the drain hose. Happy to see the engine is not showing signs of excessive wear, (it’s always a bit of a risk buying s/h) and good to see my filter choice has been vindicated.

  • Aaron Schubert September 30, 2019, 11:47 AM

    Hey Eamon,

    Good to hear its working well for you. Blowby is a pretty good indication of engine wear too, as long as you compared it to the same motor in similar situations. You may find it starts to catch more as the filter fills up more.

    All the best

  • Mic October 1, 2019, 2:25 PM

    Wife came home from work (@holden) today and said the head mechanic there was adement that we should not install anything but the hpd. My wife being someone who takes peoples word for it……and me being the guy that pisses her off with everything like this……by taking far too long (in her opinion) to make a choice. She wants something and wants it now and if it appeals to her because it looks good, sounds good and was marketed well…..she’s sold. Whereas I’ll spend 6 months googling the crap out of it until im absolutely sure on the product i decide upon. As someone else said……pay the dollars once…..the poor man pays twice. So i googled hpd and first up was this article. Ive read the whole article and everyone’s comments. Will now google the provent 200 and enquire if it will fit somehwere on the 2010 holden colorado lx-r rc 3.0L td we just bought her. 130km on the clock. Had the rocker cover gasket replaced. I then changed the oil (penrite) went on a holiday a week later (she wanted to take her flash new car instead of my reliable pos 94 model 80 series n/a slug with no electronics)……..and limp mode. Pulled out the egr sensor and wiped the oil off it and fed a rolled up tissue up the little pipe and removed that oil residue, checked all plugs and hoses etc etc……got the turbo back online. Got a mates mate to put his computer gizmo onto it…..for free…..took 30 secs…..and reset the check engine light…..(holden wanted a $147)……and i was on my way again. So about this catch can……is this egr going to give us trouble again ? Apparently its $600 for a new one. Id put a photo up of it, but its too frikkin small a piece if plastic to photograph. I hate new cars.

  • Aaron Schubert October 1, 2019, 3:53 PM

    Hey Mic,

    Western filters should sell a Provent 200 kit for your model Colorado. It’s a far better engineered piece of equipment vs the HPD, but that’s up for you to decide. I think you may find the sensor you are talking about is the MAF sensor? A good catch can will reduce or eliminate oil going back through the intake, so it won’t end up on your sensors.

    I’d be inclined to speak to a reputable mechanic or Western Filters – they should be able to answer your specific questions.

    All the best mate

  • Bill October 4, 2019, 6:46 PM

    Interesting feeds on catch cans from everyone, learnt a lot. I just got a Ryco (looks just like the Provent) for my 2007 Ranger 2.5 turbo. The unit comes without hoses and guess what, I have tried everywhere to get hoses to fit the dam thing and also the rocker cover outlet. I’m about to take it for refund as not fit for purpose. To produce a Catch Can without any hoses supplied is silly, and so am I in thinking I could just go to auto shop and buy a meter of 19mm soft oil resistant hose.

  • Aaron Schubert October 4, 2019, 8:02 PM

    Hey mate,

    Sorry to hear you are having issues with the Ryco. Take it to a dedicated hose shop, and get something that is suitable. It will be available. In WA we would use places like Couplers, Hoseco or Powell Industrial.

    All the best

  • Albert Wong October 13, 2019, 7:25 AM

    Can you share the link to order ProVent oil catch can for Landcruise 80. Thanks.

  • Aaron Schubert October 13, 2019, 4:40 PM

    Hi Albert,

    Go to Western Filters mate, and search for it.


  • Jason November 12, 2019, 9:46 PM

    Hi Aaron,
    Have you heard much about the DPF delete harness from Munji? Would be great to hear your opinion as it might save installing a catch can.

  • Aaron Schubert November 13, 2019, 5:53 AM

    Hi Jason,

    I have. I don’t like the idea of them, as firstly they are illegal, but also the DPF also does some beneficial things for the motor, despite their bad reputation. The cable keeps the EGR off by fooling the ECU. The EGR and catch cans do different jobs. I would stick with a good quality catch can and that’s it


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