Unlock Your Subaru's Boxer - No Wrenches Required
The COBB Accessport V3 is the world's best-selling, most flexible ECU upgrade for Subaru. It replaces Subaru's conservative factory calibration with COBB's Off-The-Shelf maps to deliver more power and torque, sharper throttle response, and reduced turbo lag - all through the OBD-II port in minutes. Uninstalling is just as easy: a single menu selection returns the ECU to its exact factory state.
The Accessport mounts in-cabin, taps your vehicle's data bus, and gives you a full-color gauge display for boost, AFR, throttle, and up to six live parameters at once. Data logging stores up to 10 hours of engine data for tuner review, and you can store up to 100 calibrations to switch between maps instantly.
⚠ Fitment - AP3-SUB-004. Fits 2015-2021 Subaru WRX (FA20DIT), 2015-2021 Subaru STI (EJ257), and 2014-2018 Forester XT (FA20DIT). This is the correct Accessport for these platforms - verify your model and year before ordering.
Real Gains, Backed by COBB's Maps
COBB's Off-The-Shelf maps are professionally developed for each Subaru platform and fuel grade. On the turbocharged WRX, STI, and Forester XT, Stage 1 delivers meaningful mid-range torque and horsepower over stock on pump gas - with the biggest improvement felt as reduced lag and stronger roll-on response. Stage 2 and higher unlock more when paired with supporting hardware (intake, exhaust, etc.).
Stage 1 Power Gains by Model
Because the WRX, STI, and Forester XT run different engines, Stage 1 gains vary by model, transmission, and fuel grade. Figures below are typical Stage 1 gains on an otherwise stock car running a COBB Off-The-Shelf map:
| Model |
91 Octane |
93 Octane |
| 2015-2021 WRX (6MT) |
+10-20 whp / +20-35 wtq |
+15-25 whp / +30-45 wtq |
| 2015-2021 WRX (CVT) |
+10-15 whp / +25-35 wtq |
+15-20 whp / +30-40 wtq |
| 2015-2021 STI |
+5-15 whp / +20-30 wtq |
+10-20 whp / +25-40 wtq |
| 2014-2018 Forester XT |
+11% HP / +17% TQ peak - up to +23% HP / +23% TQ at 3,000 rpm (Stage 1, 93 oct, COBB-tested) |
Wheel-horsepower (whp) and wheel-torque (wtq) figures are typical Stage 1 gains and will vary with fuel, altitude, atmospheric conditions, and vehicle condition. Forester XT figures as tested by COBB on 2014-2015 FXT vehicles. View full dyno charts and per-map power gains in COBB's AP3-SUB-004 map notes. Stage 2 and higher unlock more with supporting hardware.
ECU Map Options
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Stage 0 - baseline recalibration, no hardware mods required
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Stage 1 (91 / 93 Oct.) - full power optimization on stock hardware for each fuel grade
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Stage 2+ - additional gains with supporting bolt-on hardware
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Custom maps - load tunes from any COBB-licensed Pro Tuner for modified builds
Full-Color In-Cabin Gauge Display
Mount the Accessport V3 where you can see it. The high-resolution color screen shows boost, AFR, throttle, and up to six live parameters at once, with race, street, and dyno gauge layouts. Data logging captures up to 10 hours of engine data for tuner review.
Accessport V3 Features
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Large full-color display - high-resolution, customizable gauge layout (race, street, dyno modes)
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100 map storage - load OTS maps or custom tunes from any COBB-licensed tuner
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DTC read/clear - diagnose and reset engine codes without a dealer visit
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Data logging - record multiple channels simultaneously, up to 10 hours stored
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Performance measuring - 0-60 mph, 60-foot, quarter-mile ET and trap speed
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Shift light - custom RPM warning for perfect shifts
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Interchangeable faceplates - multiple bezel colors available
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Accessport Manager - free PC/Mac software for map management and datalog download
50-State Legal (CARB EO# D-660-43)
This Accessport carries a CARB Executive Order (D-660-43) and is legal for sale and use on emissions-controlled vehicles in all 50 states - including California - when installed per COBB's application guide for your vehicle.
Emissions
50-state legal (CARB EO# D-660-43) when used per COBB's application guide for your vehicle.
Warning: Installing this Accessport over anything other than OEM or COBB software may result in ECU failure. Designed to tune stock, unmodified ECUs only.
Fitment
Fits: 2015-2021 Subaru WRX & STI, and 2014-2018 Forester XT. Verify your exact model and year against COBB's application guide before ordering.
FAQ
Does one Accessport cover WRX, STI, and Forester XT?
Yes - AP3-SUB-004 supports all three platforms (2015-2021 WRX & STI, 2014-2018 Forester XT). It reads your vehicle and loads the correct maps.
Can I return my car to stock?
Yes - the Accessport includes an Uninstall option that reverts the ECU to exactly the factory calibration. You can also resell the Accessport after uninstalling.
Do I need a custom tune, or will the included maps work?
The pre-loaded Off-The-Shelf maps work great for stock or lightly modified cars on the supported octane grades. Custom maps are available through COBB-licensed Pro Tuners for heavily modified builds.
Is it really legal in California?
Yes - it carries CARB EO# D-660-43, making it 50-state legal when installed per COBB's guide.
