E-Tune - Subaru

E-Tune - Subaru


At iaTUNING we have a passion for personalizing vehicles, and have since our doors opened in 2003. Over the decades we’ve seen the modification world, which includes tuning, evolve considerably since it’s ‘Wild West’ days. More recently, terms such as CARB EO, and Green Speed have been thrown around the internet, which often led to further confusion, speculation, and uncertainty.

For 5+ years, Cobb Tuning has worked tirelessly on Project Green Speed. Through their program, certified Cobb ProTuners now have access to a vast library of CARB EO certified parts and ECU maps. These are the very same maps that iaTUNING implements as their baseline, which are referenced as version 4.0 and higher. As one might deduce, iaTUNING’s beliefs and business practices aim to support Cobb Tuning’s on-going efforts of the ever-evolving automotive industry.

Environmental Protection Agencyback*Note*
In alignment with Cobb, our company requires all vehicles, USA and non-USA, be equipped with the following factory Subaru parts, in good working order:

  • Downpipe. This requirement could change in the future pending the CARB EO submission process of Cobb’s GESI cat equipped downpipes.
  • EVAP system
  • TGVs
  • Air Pump system

Don't forget to click on the various tabs to read more about the tuning process: Emissions, FAQ, Tuning Background, ETC. 

How the E-Tune Process Works for Accessport and Open Source

    1. Speed Density Yes or No
    If the vehicle has a standard intake setup with the Mass Air Flow (MAF) meter, then select NO.  If you desire a tune that includes Speed Density support, whether it be full SD (no MAF), or Hybrid MAF w/ SD, then select YES from the drop down menu during purchase. If you are uncertain which setup you have then feel free to send us an email or call to verify. The majority of cars we tune will answer NO to this option. 

    2. Purchase
    For online orders, fill out and include the following details in the 'Special Instructions' section (found in the shopping 'Cart' not on the 'Checkout Page'). 

    • Make:
      Miles on Motor:
      Miles on Odometer:
      Transmission: 5MT, 6MT, or AT
      Fuel Type: 91, 92, 93, 94, e85, ETC.
      Software: Accessport v2 , v3, or Open Source?
      Modifications: Include brand and size when applicable. Example: Cobb 1050x CC Injectors. 

    3. Testing and Data Logging
    With the client's provided vehicle information, we will send the 1st map as well as detailed instructions for testing and data logging (with AP or Romraider). The 3 most common tests the vehicle will undergo are:

    • Idle Test = Vehicle sits stationary and idles at 3 different RPM targets for 2-3 minutes.
    • Driving test = Vehicle is driven in normal circumstances for 3-5 minutes in stop and go type traffic
    • Wide Open Throttle (WOT) = The vehicle will need to achieve full throttle in a pre-determined gear and pre-determined RPM zone (included in the instructions). This will require a bit of space to perform the tests safely (closed circuit track always recommended) as maximum speeds can range from 60-90 MPH. The peak speed is different for each car based on gearing and tune desires.  

    4. Review Data Logs
    After the data log files are received, we will begin the review process. Additional adjustments to the ECU will be made based on the data log review process. The revised map will then be sent back by email.

      5. Completion
      We will repeat Steps 3 and 4 until a final map is generated. On average, a finalized map is reached between 5-8 attempts. Now keep in mind, we're not here to hurry along the tune process. If the tuning process takes more than 5 revisions, then so be it. Our goal is to achieve a well rounded tune with an overall positive experience. Based on our tuning history, our first map is almost always guaranteed to start and run the engine. There is of course the exception where mechanical or electrical gremlins exist.

      Map Credits Explained

      • 1st Tuning Credit is valid for 60 days from date of purchase and is for only 1 fuel type. During the 60 days, the car must maintain the same owner, modifications, and fuel type. If a client were to install a larger turbo at day 30 then their initial tuning credit would expire and a new Repeat Client credit would need to be purchased.
      • After the purchase of the 1st turning credit, all future credits are offered at a  discounted rate for the lifetime the original credit purchaser owns the vehicle. This offer is non transferrable to new owners, nor new vehicles. Example: Client John Q completes an e-tune in 2016 and wishes to upgrade his fuel system (injectors) in 2020. They would purchase the discounted Repeat Tune Credit and a new 60 day tuning period will begin.

      • Alternations to the modification list, while in the middle of the tuning process, will require the purchase of a Repeat Clients tuning credit unless pre-authorization is received from our Tuner, Stephen Clark. 

      • A Break-in Tune is considered a separate credit from a Performance Tune credit and is used to tune an engine with brand new internals (pistons, cams, ETC). The Break-in tune has extensive focus on the drivability segment of the tune and foregoes any full throttle testing. 

      • FLEX Fuel tunes require a total of 2 credits. The 2nd credit would be purchased at the Repeat Client rate and could be purchased during or just after the 1st fuel type is tuned. Do not edit the modifications between the fuel types or this will require going back and redoing the original 1st fuel type map, which would increase costs.
      • For vehicle safety and intellectual property reasons, Accessport maps may only be opened by our in-house Certified ProTuner. Also referred to as Locked. This is a zero exception policy.

        Tuning Background

        Our experience stems past the Dyno and includes world-renowned race track testing. We are one of the few USA based Tuners to physically travel to, and tune on, highly regarded tracks such as Nurburgring and Hockenheimring. Beyond race tracks, our E-Tune program has spanned the World to Australia, UAE, Alaska, Africa, Europe, South America, and beyond. Despite the distance, we continue to treat every customer with what matters most, respect. When the time comes, consider iA-Performance for your Subaru tuning needs.

        Don't forget to click on the various tabs to read more about additional tuning items; Emissions, Trouble Shooting, Supported Parts, & Videos. 

        So why is the modification industry changing? After ~2018, long-standing emission regulations of the Clean Air Act started to receive enforcement by the Environmental Protection Agency (EPA). With that said, modifications for street driven vehicles must meet the EPA's standards in order to be considered legal for use.   

        Thankfully, several innovative companies have undergone the arduous task of obtaining EPA compliance status for various aftermarket parts, including ECU maps. Although we are no experts on the matter, and far from being attorneys ourselves, it is safe to say that California holds the highest standards for emission controls, even higher than the EPA. Items which achieve the California Air Resource Board (CARB) approval are distinguished with an Executive Order (EO). The EPA then considers a CARB EO listed part as legal for use on a street vehicle across all 50 States. Thankfully for the tuning community, Subaru specifically, Cobb Tuning has an ever-growing list of EO listed parts, including Accessports and the very tuning maps which we use as our tuning foundation (version 4.0+). For a full list of Cobb EO listed parts, please visit the following link here.  

        Following a likeminded approach, all street driven vehicles tuned by iaTUNING must retain factory functioning emission control parts, the most common of which are: Downpipe, TGVs, air pumps, and EVAP purge components.

        Our highly skilled Cobb Certified tuner not only has the knowledge of tuning, but also has a Subaru mechanic background stemming back to 2002. If issues arise, as they often do, he will be able to walk you through trouble shooting ideas and steps. This is a service hard to find amongst the tuning community. A bit of advise to all turbo charged customers, be prepared to perform a "Boost Leak Test." Hit up google for various How-To tutorials on this test

        Q: I was tuned by iaTUNING in the past. Can you open my old map and work from there? 
        A: The answer is a bit complicated. Yes, we can open the old maps, but when we save them they will adhere to the latest revision 4.0+ software. If the vehicle had deleted emission compliance parts, then the diagnostic trouble codes (DTC) will turn on with any new map version we save. 

         Q: I'm interested in tuning my car. What do you suggest I do prior to purchasing a tune credit? 
        A: First and foremost, the vehicle's standard maintenance should be up to date. Things such as worn spark plugs, dirty MAF sensor, old fuel filters, all create issues while tuning. In addition, we are strong supporters of Boost Leak Testing or Smoke Testing prior to any tuning. It sounds impossible, but a small 4mm hose leak can, and has, resulted in a 70HP power loss. With that said, make sure the engine is air tight, including the pre-turbo exhaust stream.

        Q: Does iaTUNING offer FLEX Fuel tuning?
        A: Yes, we offer Flex Fuel tuning through the Cobb accessport and current applicable platforms. Please consult with Cobb as this list continues to grow.

        Q: If I just want a map for e85, can you tune for that? Not a flex tune.
        A: Yes, we can tune for this. Before Flex Fuel tuning was relevant, it was common practice to tune 1 map for e85 and 1 map for e10 (example: 93 octane). The end user would then upload the desired map for the intended fuel type. 

        Q: Can you tune the first generation Cobb flex fuel? 
        A: We are not able to tune the first generation flex fuel sensors, or any, that require bypassing the analog output from the TGVs. Please check with Cobb to see if they offer a newer version for your vehicle, and maybe they also have a special price for repeat clients. 

        Q: My car has a pile of Cobb parts, including their prior generation downpipe and TGV deletes for flex fuel. Can you tune it?
        A: With the change to the Cobb software we are unable to defeat ECU features such as: TGVs, Air pump, EVAP purge, nor o2 sensor (cat delete). For this reason the vehicle would be in limp mode, and unable to be tuned by Cobb. 

        Q: For Open Source tuning are you able to defeat the items that Cobb does not? 
        A: So as to remain an industry trend setter with compliancy, we will hold to the same tuning rules for all platforms, Cobb and Open Source. With that said, no, iaTUNING will not deselect emission control DTCs.   

        Q: My car is a race car, what can I do to have it tuned with non-compliant parts?
        A: To prove your vehicle is a race car we will need to receive supporting documentation such as proof of State issued de-registration, or non-operable registration status, along with images of the vehicle without license plates. These documents will be kept on file at iaTUNING for a minimum of 5 years.

        Our experience covers, but is not limited to the setups below. Feel free to contact us to find out for certain if an E-tune will work with your setup. 


        • WRX 2002-present day
        • STi 2004-2021
        • Forester XT 2004-2018
        • Legacy Outback GT and XT 2004-2018
        • Baja XT - Open Source only (which we can tune), not supported by Cobb Accessport
        • Non USA market ej205, ej207, ej257 with Cobb Accessport or Open Source


        • Cobb AccessPORT (version 2 or 3)
        • Or
        • Open Source (OS)- ECU Flash, Romraider, or similar programs plus a Tactrix Cable. Note OS customers will need to send a copy of their current ROM (stock or modified is fine) after purchasing the e-tune


          • Vehicles equipped with larger than stock injectors will require the use of a wide band air fuel gauge
          • 87-120 octane, Leaded, Unleaded
          • Ethanal fuel between 0-85 (AKA e85) , this includes Flex Fuel Kits from Cobb Tuning
          • Methanol Injection
          • 440-1600cc
          • Preferred brands are: Subaru OEM, Injector Dynamics, Fuel Injector Clinic, COBB Tuning. Other supported brands are: Deatschwerks, Perrin. Known problematic brands that we try to avoid are: Power Enterprise, JECs, Five-o.


        • All Subaru 2.0L, 2.1L, 2.2L, 2.35L, 2.5L, 2.6L turbocharged engines (EJ and FA)

        Environment Conditions

        Our experience covers, but is not limited to, the following environment conditions

        • Sea Level to 12,000 feet
        • Below freezing to triple digit summer temperatures

        Flex Fuel Tuning via Cobb Accessport

        As one of the early adapters of Flex Fuel, we offer tuning support for the entire Cobb Tuning FLEX fuel line. We do not offer flex fuel tuning through Open Source as it requires defeating input signals from emission controls (TGVs). 

        Speed Density Tuning via Cobb Accessport

        Speed density tuning is supported for vehicles containing the proper equipment.

        • Cobb Accessport
        • External IAT sensor
        • Wide band air fuel ratio gauge

        Feel free to contact us for additional questions.  

        The following videos offer an in depth look at installing, and data logging with, the Version 3 Accessport. Thanks goes out to Cobb for the video content. 

        Install v3

        How to Data Log

        Customer Reviews

        Based on 142 reviews

        Amazing tuner! Great communication and great people!!

        joseph kolon
        e tune

        Getting etune was a breeze. Thanks too.
        I.e. Tuning did a amazing job.
        Car drives like it came that way just better.
        Would recommend to everybody

        Jose P
        Excellent First Time

        Stephen Did a Excellent Job with my tune, the car is running great after adding some mods and supporting mods. it was previously tune in a dyno and now its making even more power. I will definitely return to Stephen some time soon to retune after some more added mods. Stephen was patience and would answer any questions timely.

        Committed Tuner and Satisfied Customer!

        Stephen did a great job with my tune. Now I have a safe numbers, with much improved power results.
        My setup is a jdm ej205 avcs engine with a vf48 turbo + supporting mods.
        Stephen was very patient, responsive, organized, and committed to the end goal of getting the tune completed. My setup had some gremlins along the way, but with Stephen’s input and patience, I was able to complete the tune.

        This was my first time e-tuning, prior to this I had a dyno tune. Having gone through this process, I would not hesitate to do another e-tune with IA tuning.

        Perfect First Tune Experience

        Great first experience with tuning and to the Subaru community! I highly recommend iA tuning if you want a safe and powerful tune!
        Stephen did a fantastic job communicating with me on a daily basis and sending me regular tunes to upload after logging, and troubleshooting issues that arose with me. I did end up utilizing the full 60 days with holidays and a few minor issues that plagued the process part way through tuning. Stephen was able to help me find the issue (failed OEM BPV diaphragm) with limited info and then worked with me to resolve the problem and keep pushing forward with the tune. We did have strange fall weather here in VA and the temps ranged from 80F to 27F in the same week. The car has performed great and is making more power safely and much happier than the OTS map (prior to mods) with basically just reliability mods as I have not yet ventured down the rabbit hole of power. I do plan on using iA tuning in the future for all my E-tuning needs as I am very pleased with the product and the professionalism and knowledge of Stephen. His punctuality and promptness was very nice; if you sent him the information needed from a log along with a short description of the driving characteristics and how the car responded to the tunes he usually responded back within 24-36hrs (within his business hours and with time zone). I counted Saturday as a bonus day for me if he replied as it is a weekend and his hours a limited--he still followed through frequently.

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