Unichip UNI-X +
Intake Clean +
Provent 200 Catch Can

After several years very happily running a Unichip Q4 performance chip on the 200 series, I received a call from Dynomotive, the Australian Unichip distributer, offering an upgrade to the new version, known as the UNI-X ECU.

With almost 140,000 kilometres on the 200, I also decided to have the intake cleaned to remove the oily carbon buildup that results from the Exhaust Gas Recirculation (EGR) system.

At the same time, Dynomotive also installed a Provent 200 catch-can, which reduces the oily fumes reaching the intake and should therefore reduce the carbon buildup in the future.

Finally, with a few starter-motor issues following our Cape York trip, Dynomotive also installed a new starter.

Jump to:  uni-x | Intake clean | Catch can

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Not all performance chips are the same

I had a Unichip Q4 installed in the 200 over four years ago. In that time it has performed flawlessly, so when Dynomotive offered me a free upgrade to the new Uni-X, I had no hesitation in accepting.

The original Q4 installation article is quite comprehensive, so I won't repeat all of that information here. What I will do is summarise what I like about the Unichip and why I prefer it to the alternatives, most notably a rail chip or remap.

The first thing to keep in mind when considering a performance chip or remap, is that there are vast differences between their capabilities. Unichip refer to the Uni-X as an additional ECU, rather than a chip. And it's an accurate description. While most chips are extremely basic (but overpriced) devices, the Uni-X has a large amount of computing power, which allows it to do things that are completely beyond the abilities of a standard rail chip.

In the last article I discussed a few other types of chips, and briefly mentioned remaps. This time I'll just talk about one other type of chip, and go into remaps in more detail.

Fuel rail chips

fuel rail chip DP

Last time I wrote about the limitations of fuel rail chips, it resulted in legal threats from the company behind one of the better-known brands in Australia. Apparently, revealing how rail chips work -and why they are obsolete technology- wasn't something they wanted people to read! But that obsolescence has only become more obvious over the last few years as technology has continued to evolve. I really can't see why anyone would bother buying one today.

A fuel rail chip plugs into the common rail pressure sensor and fools the ECU into demanding more fuel pressure. This results in more power. It's a blunt instrument using 20-year-old technology, wrapped in a new enclosure.

Despite some logic-defying claims, a rail chip doesn't work with the vehicle's computer and it doesn't control injector timing. The ECU has no idea the chip is there, so how can it possibly work with it? A rail chip intercepts and modifies the signal between the common rail pressure sensor and the vehicle's ECU, causing increased fuel pressure. Nothing more, nothing less.

ECU Remaps

ECU remap tableThere has been explosive growth in remapping in the years since I installed the Unichip Q4. It seems everybody with a mechanical workshop and a laptop has become an overnight expert in extracting more power from diesels.

A remap can adjust fuel pressure, injector duration, injector timing and turbo boost. It's written into the vehicle's ECU, overwriting the factory programming for some or all of these parameters. Typically, a remap begins with a base file written by a tuner. The installer then flashes this tune into the factory ECU and tests the vehicle on a dyno. They will then likely make some adjustments to the map, then reflash the ECU again. This process continues until the installer is happy with the new programming.

The major problem with remaps from my perspective is that they are only as good as the person creating, installing and tuning them. There is no formal training or standards and no consistency between installers. Some remaps are excellent, some are average and some are dangerous, with only word of mouth and reputation to guide you towards the right one. There are undoubtedly some great tuners out there, but the industry is being damaged by many others.

Chips include Roo Systems, Steinbauer, DP Chip, Unichip and Safari Armax

Unichip Uni-X

Uni-X D8D driverA Uni-X ECU offers the respective advantages of remaps and chips, without their limitations. It controls fuel pressure, but unlike a rail chip, it can also control fuel timing, duration and boost. A Unichip offers similar performance to a good remap, but has the advantages of being removable and offering multiple user-selectable settings.

The bottom line, is that if I were starting from scratch again today, I would undoubtedly choose a Unichip, primarily for the following reasons:

  • 5-map select: This is the Uni-X's biggest advantage. A remap is one-size-fits-all, which is typically the maximum power the tuner can extract. This will deliver great performance, but there's no ability to wind it back and give better economy when you want it. With a remap, there's no option to have different settings for different driving conditions, changeable at the touch of a button (or via a phone app). Rail chips typically have different settings, but they are usually controlled from under the bonnet.
  • More safety: The Uni-X runs the factory tune until you reach operating temperature, reducing excess strain on a cold engine. Neither a remap or rail chip does this. At the other end, the Unichip also starts winding back the tune once water temperature exceeds 90º, ensuring factory safety parameters are unaffected. This means that if you're driving in extreme conditions, such as towing a big van up a long hill on a hot summer's day, there is no additional engine stress imposed by the Unichip. Conversely, a rail chip will keep adding extra fuel pressure above what the ECU is demanding, no matter what's happening to engine temp. Because a rail chip doesn't;t measure engine temp. Remaps generally work similarly, continuing to add fuel/boost above what the factory settings would be, irrespective of engine temperature changes.
  • High-idle map: I added this with the Uni-X. One of my maps now has an 1000rpm idle set. Given the absence of a standard idle-up function on the 200 series, this is a fantastic feature for charging batteries or running a winch. This functionality is impossible with a remap or rail chip.
  • Live tuning: The Unichip comes with 5 preset maps. But it's then live tuned on the dyno to get the best out of it on every map. The tuner can monitor and modify the tune to suit your particular vehicle while it's still running on the dyno. Seeing the changes reflected instantly. This isn't possible with a remap, which must be reflashed after each change and then run on the dyno again to retest the tune.
  • No evidence it was installed: Concerned about new vehicle warranty? If you remove a Unichip, there is no evidence stored in the ECU that it was ever installed. However, every time you remap the LandCruiser's ECU, it's logged. A Toyota dealer can read how many times this has occurred. Typically, several numbers are added to the flash count to complete a quality remap. If you completely remove a remap before you go to the dealer, that actually adds another flash to the counter, making it even more obvious to the dealer that a remap has been installed.
  • Loss of remap after factory updates: Toyota periodically update ECU software during routine servicing. This update will overwrite your performance remap, meaning you have to return to the tuner to get it put back in, although most reputable tuners will perform this service at no additional cost.

People may say that there's no point having 'power' and 'economy' modes....That you can just drive less aggressively and achieve the same results. But that isn't entirely true. The higher power settings on the Uni-X (and those of a power-focussed remap), make more aggressive changes to the various parameters. So while driving style certainly effects economy, the engine map also has an effect. Put simply, you can still achieve better economy running the economy map, than you can by driving more economically on the power map (or with a remap).

Comparing the Uni-X to the Q4 I was running previously, the Uni-X has several improvements. In my case, the most important changes are the waterproof enclosure allowing placement in the engine bay without risk from deep water crossings, plus the space saving thanks to the single D8D injector driver rather than the twin drivers required for the Q4.

Although I won't be making use of them, the Uni-X also adds new functionality including the ability to correct the factory speedometer. This is very useful when running oversize tyres, as road authorities and engineers require ADR-compliant speedo accuracy. Another improvement is that the main processor in the Uni-X is much faster than the Q4, making live-tuning on the dyno faster and more accurate.

But you got it for free!

Yes, Dynomotive supplied and installed the Uni-X for me at no cost. Although I haven't been paid anything to promote it. Does that make me biased against remaps or other chips? I'm going to say no, for two reasons. First, when I bought the 200 I already had a good quality rail chip I could have installed at no cost. I gave it away.

I have also been offered free remaps and rail chips for the 200 on several occasions. In other words, I've had free options for rail chips, remaps and a Unichip. And the Unichip was -and still is- my preference.

Chips include Roo Systems, Steinbauer, DP Chip, Unichip and Safari Armax

Intake Clean and Starter Replacement

Before installing the Uni-X, I asked Dynomotive to dismantle and clean the intake of the 200 to remove the years of oily buildup.  At the time of writing, the cost of this is $1826 for a complete clean I had done, or $880 for just the upper section. Removal of the inlet manifolds and associated components is also required to access the starter motor, which had begun to play up following the deep water crossings we completed the Old Tele Track. Given the difficulty accessing the starter (Toyota quote 16 hours of labour to replace it!), I strongly suggest that it be replaced at the same time as an intake clean is undertaken. You can buy genuine Denso starters online for under $500, which is a fraction of the labour cost to access it. Assuming an intake clean every 150,000km, the starter is probably getting close to end-of-life anyway, so it makes sense to change it at the same time and save the potential labour costs of needing to replace it soon afterwards.

Why does the intake need cleaning?

Most modern diesels have an emission reduction system called Exhaust Gas Recirculation (EGR). This system recirculates a small amount of exhaust back into the engine to reduce Oxides of Nitrogen (NOx) in the exhaust gasses.

This recirculated exhaust combines with oily vapour from the crankcase ventilation to cause a gradual buildup of black oily residue in the intake system.

While it's technically possible to disable the EGR system, it is illegal to do so. Individual fines of up to $250,000 apply. Same goes for DPF systems on later models. While you're unlikely to get caught, it's worth knowing that NOx is pretty nasty stuff, being a major cause of visible smog, asthma and other respiratory diseases. The less of it floating around in our air, the better. For these reasons I will not disable the EGR system to save having to do an intake clean every 5 years or so.

Why not a DIY intake clean?

I generally enjoy doing my own maintenance, but this time I decided to leave it to the pros. It really is a big and dirty job to clean out the intake, and honestly, I just didn't want to do it! Watch the full time-lapse video below and you'll see just how much is involved. There are also risks of dropping bolts into the heads and fuel leaks from the high-pressure common rail system if not reassembled correctly.

Provent 200 Catch-Can installation

One potential way to reduce the oily buildup in the inlet manifold is to install a 'catch can' between the crankcase and the inlet manifold. Oily vapour coming out of the crankcase passes through the catch can, which (as the name implies) catches most of the oil, with the remaining vapour continuing to the inlet manifold.

The premise of the catch can certainly makes sense, and it can't do any harm. Time will tell how effectively it reduces the build up. I plan on having the intake cleaned again after another 140,000km to see what difference the catch can has made.

There are several brands of catch can available. Based on various independent tests, the Provent 200 from German company MANN+HUMMEL is the most suitable for the 200-series. Don't run a smaller can, as it may not cope with the vapour volume of the 1VD engine. There are various mounting systems available for the 200-series, depending on where you have space. Complete DIY kits are available which locate the catch can near the brake fluid reservoir and firewall. This isn't suitable for me due to my accessory fusebox, so Dynomotive installed the can using one of their kits to place it between the grille and radiator. The Dynomotive kit is also available for DIY installation if you so desire, which is a pretty simple job. The downside of this location is the potential for condensation if you make regular short trips, so if you can use the kit that places the can near the firewall, it could be a better choice.

No matter the mounting location, installation is quite simple with Dynomotive completing the install in less than an hour. It's simply a matter of mounting the unit in the chosen location, then running the lines between the unit and the vent on the passenger-side valve cover. You may also need to run a line from the Provent's drain valve, depending on where you've mounted the unit.

The catch-can should be checked and drained of any oil at the same time as your regular service interval. There's a filter element inside the can, which typically lasts around 40,000km between changes. Oil seeping from the lid of the can is an indication that it requires replacement.

Uni-X Results

I expected that the results between the Unichip Q4 and Uni-X would be similar, and that was indeed the case. I won't post the original Q4 Vs Uni-X dyno sheets, because there's too much variation in the testing conditions. The dyno used for the Q4 was 2WD, the Uni-X was 4WD. The tyres were also different, and the vehicle is 100,000km older.

At the time of writing, I've been running the UNI-X for over five months and around 10,000km. With the Q4 I typically ran the 'Economy' tune. With the UNI-X I found the 'economy' tune delivered the same performance as the Q4 and slightly better economy. This could be a result of the improved tune in the UNI-X, or it could be a result of the intake clean, or a combination of the two. Either way, I've now changed to the 'Towing' tune on the UNI-X, which seems to deliver the same economy as the Q4 did on 'Economy', but also slightly improved performance, sitting between 'economy' and 'performance' on the dyno runs.

Standard Vs Unichip Uni-X

This graph is essentially a "before and after", showing the Uni-X's Performance, Economy and Towing tunes compared with standard (factory) output. The dyno runs were undertaken on a 4WD dyno, and show the power/torque 'at the wheels'.

As you can see, there is considerable difference between all of the Unichip's tunes.


After almost 5 months, I'm still loving the UNI-X. A great combination of performance and fuel economy, and I've suffered no problems whatsoever.

I've already used the high-idle tune several times, and I highly recommend it. It's something I should have done when I first installed the Q4.

The buildup of goo in the intake was roughly the amount I'd expected to see. I'm not convinced it was having an effect on economy or performance. As mentioned, I did see a light improvement in economy and no obvious performance change after the clean. But the economy improvement could have been a result of the UNI-X, rather than the clean itself. Either way, I would suggest an intake clean is worth doing at around 150,000km intervals. There's no doubt that an excessive buildup would have an effect on performance at some stage.

Catch-cans are popular, and mine has accumulated about 200ml of oil after 10,000km. That's 200ml that hasn't gone through the intake, so it should reduce sludge buildup in the future. Only time can confirm this, however. I'll compare the results at the next intake clean, if I still have the car in another 6 years!

Any questions, please fire away in the comments section below.

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