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Does your Subaru need a New PCV Hose Kit?
May 26, 2023
Hello Subaru enthusiasts! Here at Flatirons Tuning, we understand the significance of maintaining your Subaru to keep it running at peak performance, no matter if you are driving at the track, to work, or out on an Overlanding expedition. One crucial component that often doesn't get the attention it deserves is the PCV (Positive Crankcase Ventilation) hoses. These hoses are pivotal in ensuring proper engine performance and longevity, and we've put together a comprehensive set of Subaru OEM and Roger Clark Motorsport kits to suit your specific Subaru model.
All Turbo Subarus have a set of PCV hoses (Positice Crankcase Ventilation) which connect the crankcase to the intake to capture any gasses and send them to the inlet to be cycled through the inlet and exhaust. There are a number of hoses in this system, and many of them are somewhat small, and as they age, the factory hoses can become hard and potentially not seal as well, or even crack.
Because Turbo Subaru's like the WRX and STI use a Mass Air-Flow system to meter the air that is going into the engine, any cracks or leaks of the PCV system ( which is connected to the turbo inlet behind the Mass Air-Flow sensor) can introduce an error to the amount or air that the MAF is reading. That error can result in a lean running condition which can cause drivability issues, check engine lights, and even damage to the engine in an extreme case.
To get an ideal of what the PCV system looks like, we have put together a video where we look at the different parts of this system which might be helpful:
Click here to watch our video talking about the WRX and STI EJ255 and EJ257 PCV system
We also have a video looking at how you can tell if your PCV system is working properly - Click Here:
If it has been a while since you checked your PCV hoses, they are always worth checking to make sure that they are still sealing properly, and to replace any that aren't. If you aren't sure, but you are having any issues that could be related to a vacuum leak, etc., the best thing you can do is to smoke test your car which is a very effective test to ensure that your PCV hoses are sealing properly.
It is worth mentioning here if you have installed an Air Oil Separator to your car, this ties into your PCV system, so most likely the majority of the hoses that are part of the AOS have replaced the OEM PCV hoses. But there may still be some factory hoses left, and if you are installing an AOS, you will want to take a look at any hoses that are kept to make sure that they are in good shape.
If you are going through your car, or doing a build and you want to simply replace all of your PCV hoses so that they are all new, we have put together comprehensive PCV Hose Kits for your WRX, STI, and most Turbo Subaru's so you can get all of the hoses that you need in a complete kit so you don't have to look for them individually.
Here a links to those kits:
2004 - 2005 Forester XT PCV Hose Kit
2005 - 2006 Legacy GT and Legacy GT Spec-B PCV Hose Kit
2007 - 2009 Legacy GT and Legacy GT Spec-B PCV Hose Kit
Roger Clark Motorsports has been working with Samco to create Silicone Hose kits that replace the OE hoses for lots of Subaru's. They have put together an Oil Breather Hose kit for the 2008 - 2014 WRX and STI which is a great option as well:
Hopefully this helps you find the PCV hoses that you need. If you are having any trouble at all finding hoses for your car, or if you aren't sure what kit you need, please open a ticket or Live Chat with us on our site and we'll do our best to help.
Thanks for your support!