Moroso Air Oil Separator

Part #: MOR 85484
MSRP: $406.64



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Brand: Moroso
Color: Silver
Installation Hardware Included: Yes
Material: Aluminum
Mfgr. Warranty: 90 Days
Return Policy:

RallySport Guarantee - 30 Days

Items that are covered under the RallySport Guarantee offer a 30 day no questions asked return policy.

RallySport Guarantee items may be returned within 30 days of the original invoice date and must include all the original parts and contents for a refund.

The RallySport Guarantee does not apply to products that have been modified, damaged, misused or abused. All returns require an RMA (Return Merchandise Authorization) Number, and freight charges are strictly non-refundable. For more information regarding our freight refund policy, please refer to our return policy page found HERE.


Subaru Impreza
WRX STI 2004,2005,2006,2007WRX STI Limited 2007WRX TR 2006,2007WRX Limited 2006,2007WRX 2006,2007

From the factory excess crankcase vapors, residual oil and moisture are vented back into the intake manifold and crankcase ventilation system. This can coat the pistons and everything else with a detonation prone layer of oil. This is no good in a turbocharged vehicle.

Moroso has come up with a 2 tank system that allows the factory crankcase ventilation to operate how it was designed. No other system on the market does this.

Billet Aluminum bodies compliment any engine compartment and can be polished, chromed or powder coated for a custom look. Each Separator has a billet aluminum clamp, a bottom drain with an elbow that makes draining the collected oil a mess-free operation. Includes stainless steel mounting brackets, 1/2" inlet and outlet fittings, 66" of 3/8" diameter and 66" of 1/2" diameter rubber hose for plumbing the Air-Oil Separators inline.

This is for cars with a TMIC and stock location turbo. This kit is not designed to be used with a FMIC or rotated mount turbo.





  • AnswerQ: 05 WRX  RAWeiss9124717 9 months ago

    So ideally with the cruise control disconnected/removed this AOS should work on my 05 WRX? Theres no other specific fitment issues?

    • A: If the cruise control is removed, then this should work on your 2005 WRX. Unfortunately Moroso has not been able to guarantee this, but that is what we have found.

      Zach G. 9 months ago

  • AnswerQ: strut tower bars  AznCuddy 9 months ago

    Would the Cusco strut tower bar clear this product?

    • A: We have not fitted the Cusco strut tower bar with this product and have not had the ability to confirm fitment at this time.

      Nick S. 9 months ago

    • A: We Have not tried fitment with the Cusco Tower Brace at this time. I have looked at a few photos online and have a strong feeling it will clear as long as the cans are dropped down.

      Moroso Performance 9 months ago

  • AnswerQ: Grimmspeed Turbo Heat Shield  Richsta4249299 1 year ago

    Can you confirm fitment with a grimmspeed turbo heat shield.

    • A: We have not seen any issues with this AOS and an aftermarket heat shield.

      Spencer H. 1 year ago

    • A: I cannot at this time, It is designed to be used with an OEM heat shield. However it very well may fit.

      Moroso Performance 1 year ago

  • AnswerQ: moroso aos   matt_ruby_1196140 1 year ago

    will this fit an 04 STi seeing as they do not have a cable throttle

    • A: This will fit a 2004 STI.

      Zach G. 1 year ago

    • A: Yes this kit fits 2006-2007 WRX as well as 2004-2007 STI with Top Mount Intercooler.

      Moroso Performance 1 year ago

    • A: I uploaded a photo in the photos section that may help.

      Moroso Performance 1 year ago

  • AnswerQ: FMIC?  solomon06 2 years ago

    I own a 2006 WRX and was wondering is there instructions for installing it on a front mounted Subaru?

    • A: This is not a confirmed fit with a TMIC and will not include instructions on how to install with a FMIC.

      Spencer H. 2 years ago

    • A: Moroso does not publish installation instructions for FMICs, but the install will essentially be the same other than the rerouting the PCV hoses that are normally attached to the intercooler.

      Zach G. 2 years ago

    • A: We actually do have instructions for a 2006 STI with front mount intercooler you can use these as a reference although they are not exactly the same. All plumbing should be near identical.

      Moroso Performance 2 years ago