Flex Fuel E-Tune (Open Source) – 2006-2014 WRX / 2004-2020 STI

Tuning DOES NOT fix mechanical issues or misfires. Tuning is for vehicles that are already in good running condition.  Tuning is for making aftermarket parts work properly together.

Checklist:

Fuel Related Pre Tune Checks

• Do you have the fuel octane you want to be tuned on in your tank? – It is critical you have the fuel you want to be tuned on in your fuel tank when you come in for the tune. We can only tune your car for the fuel that is in the fuel tank. If you tune on 93 octane you will make more hp but you can damage your engine if you boost with 91 or 92 octane in your vehicle. If you want to be able to run 91, 92, or 93 then you will want to tune your vehicle with 91 octane in it.
• Do you have nonoxygenated 91, a.k.a. no ethanol 91, ethanol-free 91 in your fuel tank? – We do NOT  recommend running 91 non oxy or non ethanol fuel (see images below for examples). We have found turbocharged Subaru’s do not like this fuel and it acts like a much lower octane in real life testing. We will tune your car on that fuel and you will make substantially less hp. If you decide to come back with a better fuel you will have to pay for a tune adjustment (e-tune hourly rate). If you only have access to 91 non oxy, we have found an aftermarket intercooler can help keep the power where it’s supposed to be.
  • We have found that most Kwik trips in Minnesota have nonoxygenated 91 and the pump is not always labeled non oxy, so we recommend staying away from them for pump gas.
• Is your MAF (mass air flow) sensor dirty?– We recommend cleaning your MAF with MAF cleaner before your tune. If we tune your car with a dirty or bad MAF, if you ever decide to clean or replace it your tune will likely be off and you will need a new tune (we DO NOT recommend using aftermarket MAF sensors, even if it’s the same brand as the OEM they can read differently than stock and typically don’t last as long. Always buy OEM from the dealer)
• Does your front O2 sensor operate correctly?– If your front O2 sensor is not working we can NOT tune your car. (we DO NOT recommend using aftermarket O2 sensors, even if it’s the same brand as the OEM they can read differently than stock and typically don’t last as long. Always buy OEM from the dealer)
• Check or replace your fuel filter
• Check/set fuel pressure. (If you installed an aftermarket adjustable fuel pressure regulator you need to set it. All aftermarket fuel injectors are flow rated at 43.5psi. That is the recommended base pressure for you to use. Always set base pressure with a warm engine and the vacuum line disconnected from the fpr and plugged.)
  • Stock Fuel Pressure from the Manufacture
  • All turbo EJ Subarus- 41-46psi

Boost Related Pre Tune Checks

• Verify no boost/vacuum leaks. If you recently installed a front mount intercooler / piping or had your engine apart a boost/vacuum leak test is a must!
• Clean or replace your air filter
• If tuning 02-14 WRX/04-07 STI models for over 22 PSI an aftermarket MAP (manifold absolute pressure) sensor is required
• If tuning 08-2021 STI models for over 26 PSI an aftermarket MAP (manifold absolute pressure) sensor is required

Engine Mechanical Related Pre Tune Checks

• Perform a compression test– knowing the health of your engine before the dyno tune is critical to make sure you get the most out of your tune. Compression should be within 10% on all cylinders.
• How many miles are on your spark plugs?– If you don’t know the history of your spark plugs please replace them beforehand. If your car misfires from a bad or improperly gapped spark plug on the dyno we can not complete the tune until that issue is resolved
• We CANNOT tune with misfires
• Do you have any oil, coolant, or transmission fluid leaks.– All leaks should be addressed before your e-tune. 
• When is the last time you changed your engine oil?–  We recommend having fresh engine oil to help prevent engine failure at higher RPMs. Mobil 1 and Royal Purple are NOT recommended in turbo Subaru engines.
  • For the EJ engines, we recommend Rotell T6 5w40, Motul 8100 X-cess 5w40, Motul 6100 Synergie 10w40 (good for E85), or Motul 300v 5w40, 15w50.
• Does your car overheat at idle or under load?– Your cooling system should be properly burped and be able to keep your car form overheating at idle or when driving.
• Do you have any exhaust leaks?– exhaust leaks can cause the AFR sensors to read inaccurate and potentially cause the tune to be incorrect.
• Do you have any check engine lights on?– Your car should NOT have any check engine lights on when you come in for the tune.

Vehicle General Maintenance and readiness to strap on the Dyno Pre Tune Checks

• Are your tires properly inflated?– Make sure tires are fully inflated to the correct pressure (30-40psi recommend) 
• Does your car drive strait down the road?– Your car should have a proper wheel alignment.
• Is your clutch up to the task of holding more power?– Make sure your clutch is not slipping and able to handle the torque for the upgraded mods
• Does your battery and charging system operate correctly?–If the battery dies while flashing a tune on the car it can brick the ECU, leaving you with a car that will not run. If your car has to be jumped every time to start it needs a new battery in order to be tuned.
• How old are your Transmission, Rear Diff, and Transfer Case(where applicable) fluids?– make sure these fluids are fresh and full .