Optimize your Subaru STI 2015-2021 engine's performance with a comprehensive range of top-quality aftermarket parts from industry-leading brands. Elevate the power and efficiency of your vehicle with ETS, HKS, Perrin, Mishimoto, AMS, Grimmspeed, Cobb, Remark, PLM, Turbosmart, IAG Performance, and more. Enhance airflow and filtration through AIR INTAKE DUCTS and COLD AIR INTAKES, while maintaining engine cleanliness with AIR OIL SEPARATORS and CATCH CANS. Experience impeccable control and responsiveness with BLOW OFF VALVES and BOOST CONTROL SOLENOID COVERS, complemented by the reliability of ENGINE MOUNTS and meticulously crafted ENGINE MANAGEMENT HARNESSES. Simplify maintenance and improve overall performance with DIPSTICKS and explore comprehensive ENGINE PACKAGE DEALS for a holistic approach to upgrading your Subaru WRX's engine. Unleash the full potential of your vehicle through precision-engineered components designed to deliver both power and durability, all meticulously designed to give your Subaru STI the edge on the road or track.
2015-2021 Subaru WRX STI Engine Parts
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![FactionFab [15 - 21 WRX, 15 - 18 STI] Axle Back Exhaust Polished Tip | 1.10204.1 - JDMuscleAxle Back Exhausts1.10204.1](//jdmuscleusa.com/cdn/shop/files/factionfab-15-21-wrx-15-18-sti-axle-back-exhaust-polished-tip-1102041-5689418.jpg?v=1770327979&width=220)
![FactionFab [15 - 21 WRX, 15 - 18 STI] Axle Back Exhaust Polished Tip | 1.10204.1 - JDMuscleAxle Back Exhausts1.10204.1](//jdmuscleusa.com/cdn/shop/files/factionfab-15-21-wrx-15-18-sti-axle-back-exhaust-polished-tip-1102041-1324329.jpg?v=1770327979&width=220)
FactionFab Axle Back Exhaust Polished Tip | 1.10204.1
Fits: 15-21 WRX, 15-18 STI
Regular price $390.00Sale price $390.00 Regular priceUnit price per$390.00 -
![Killer B Motorsports [02 - 07 WRX, 04 - 21 STI] 3" Cast Turbo Inlet to 84mm Adapter Coupler | TIEJC84 - JDMuscleTurbo Inlet Hoses and PipesklbTIEJC84](//jdmuscleusa.com/cdn/shop/files/killer-b-motorsports-02-07-wrx-04-21-sti-3-cast-turbo-inlet-to-84mm-adapter-coupler-tiejc84-6849084.jpg?v=1770327976&width=220)
Killer B Motorsports 3" Cast Turbo Inlet to 84mm Adapter Coupler | TIEJC84
Fits: 02-07 WRX, 04-21 STI
Regular price $49.00Sale price $49.00 Regular priceUnit price per$49.00 -
IAG Performance Replacement Blow Off Valve Elbow Black
Fits: 02-07 WRX, 04-21 STI
Regular price $59.99Sale price $59.99 Regular priceUnit price per$59.99 -
Up to $15.25 off
In StockPerrin 06-14 WRX / 07-21 STI / 12-16 Impreza / 06-13 FXT / 05-09 Legacy Alternator Pulley Red | PSP-ENG-119RD
Only 6 leftRegular price $45.75Sale price $45.75 Regular priceUnit price per$61.00 -
![IAG Performance [02 - 14 WRX, 04 - 21 STI, 05 - 12 LGT, 04 - 13 FXT] 8mm Thick Phenolic Spacers | IAG - AFD - 3104 - JDMusclePhenolic Thermal Intake Manifold SpacersIAG-AFD-3104](//jdmuscleusa.com/cdn/shop/files/iag-performance-02-14-wrx-04-21-sti-05-12-lgt-04-13-fxt-8mm-thick-phenolic-spacers-iag-afd-3104-4678295.jpg?v=1770327978&width=220)
IAG 8mm Thick Phenolic Spacers
Fits: 02-14 WRX, 04-21 STI, 05-12 LGT, 04-13 FXT
Regular price $74.99Sale price $74.99 Regular priceUnit price per$74.99 -
IAG 04-21 STI Big Bore 76mm Throttle Body w/ Electronics & Adapter Intake Manifolds | IAG-AFD-2027SL
Regular price $414.99Sale price $414.99 Regular priceUnit price per$414.99 -
Up to $17 off
In StockTurbo XS WRX/STi 3in Downpipe to OEM Cat-Back Adapter w/OEM Donut Gasket | ADA-3DP-OEMCB-2
Regular price $56.00Sale price $56.00 Regular priceUnit price per$73.00 -
![MBRP [15 - 21 WRX/STI] 3inch Cat Back Dual Split Rear Exit T304 with Carbon Fiber Tips Street version | S48003CF - JDMuscleCat Back Exhaust SystemMBRS48003CF](//jdmuscleusa.com/cdn/shop/products/mbrp-15-21-wrxsti-3inch-cat-back-dual-split-rear-exit-t304-with-carbon-fiber-tips-street-version-s48003cf-1108331.jpg?v=1770329143&width=220)
![MBRP [15 - 21 WRX/STI] 3inch Cat Back Dual Split Rear Exit T304 with Carbon Fiber Tips Street version | S48003CF - JDMuscleCat Back Exhaust SystemMBRS48003CF](//jdmuscleusa.com/cdn/shop/files/mbrp-15-21-wrxsti-3inch-cat-back-dual-split-rear-exit-t304-with-carbon-fiber-tips-street-version-s48003cf-4543361.png?v=1770329144&width=220)
Up to $269.41 offMBRP 3inch Cat Back Dual Split Rear Exit T304 with Carbon Fiber Tips Street version | S48003CF
Fits: 15-21 WRX/STI
Regular price $1,144.99Sale price $1,144.99 Regular priceUnit price per$1,414.40 -
Subaru OEM Muffler Exhaust Gasket Most Subaru Models | 44022AA131
Regular price $10.55Sale price $10.55 Regular priceUnit price per$10.55 -
IAG 02-14 WRX / 04-21 STI / 05-12 LGT / 05-09 Outback XT / 04-13 FXT Stage 2 CNC Ported 11mm Oil Pump | IAG-ENG-2240
Regular price $479.99Sale price $479.99 Regular priceUnit price per$479.99 -
IAG 02-14 WRX, 04-21 STI, 05-09 LGT, 04-13 FXT 550 Street Cylinder Heads Package | IAG-ENG-H550NE
Regular price $3,399.99Sale price $3,399.99 Regular priceUnit price per$3,399.99 -
IAG PTFE Fuel Line Kit
Fits: 08-14 WRX, 08-21 STI
Regular price $499.99Sale price $499.99 Regular priceUnit price per$499.99 -
![ETS [15 - 21 STI] Stock Turbo Piping Kit - JDMuscleIntercooler Piping Kits200-30-ICP-001OEM - 1.75"Stock BOVStock](//jdmuscleusa.com/cdn/shop/products/ets-15-21-sti-stock-turbo-piping-kit-1940460.jpg?v=1770329054&width=220)
ETS Stock Turbo Piping Kit
Fits: 15-21 STI
Regular price From $795.00Sale price From $795.00 Regular priceUnit price per$795.00 -
In StockCOBB Oil Filler Cap Black Most Subaru Models
Only 7 leftRegular price $95.00Sale price $95.00 Regular priceUnit price per$95.00 -
![Remark [15 - 21 WRX/STI] Stainless Steel Axle Back w/ Double Wall 4 Inch Polished Tips | RO - TSVA - D4 - JDMuscleAxle Back ExhaustsremRO-TSVA-D4](//jdmuscleusa.com/cdn/shop/products/remark-15-21-wrxsti-stainless-steel-axle-back-w-double-wall-4-inch-polished-tips-ro-tsva-d4-3491771.jpg?v=1770329774&width=220)
![Remark [15 - 21 WRX/STI] Stainless Steel Axle Back w/ Double Wall 4 Inch Polished Tips | RO - TSVA - D4 - JDMuscleAxle Back ExhaustsremRO-TSVA-D4](//jdmuscleusa.com/cdn/shop/files/remark-15-21-wrxsti-stainless-steel-axle-back-w-double-wall-4-inch-polished-tips-ro-tsva-d4-8083148.jpg?v=1770329774&width=220)
In StockRemark Stainless Steel Axle Back w/ Double Wall 4 Inch Polished Tips | RO-TSVA-D4
Fits: 15-21 WRX/STI
Only 15 leftRegular price $695.00Sale price $695.00 Regular priceUnit price per$695.00 -
![Mishimoto [08 - 14 WRX / 08 - 21 STI] Silicone Radiator Hose Kit Neon Yellow | MMHOSE - STI - 08NY - JDMuscleRadiator HosesmisMMHOSE-STI-08NY](//jdmuscleusa.com/cdn/shop/products/mishimoto-08-14-wrx-08-21-sti-silicone-radiator-hose-kit-neon-yellow-mmhose-sti-08ny-9748599.jpg?v=1770329892&width=220)
![Mishimoto [08 - 14 WRX / 08 - 21 STI] Silicone Radiator Hose Kit Neon Yellow | MMHOSE - STI - 08NY - JDMuscleRadiator HosesmisMMHOSE-STI-08NY](//jdmuscleusa.com/cdn/shop/products/mishimoto-08-14-wrx-08-21-sti-silicone-radiator-hose-kit-neon-yellow-mmhose-sti-08ny-3106639.jpg?v=1770329892&width=220)
Up to $16.05 off
In StockMishimoto Silicone Radiator Hose Kit Neon Yellow | MMHOSE-STI-08NY
Fits: 08-14 WRX / 08-21 STI
Only 5 leftRegular price $155.95Sale price $155.95 Regular priceUnit price per$172.00
![FactionFab [15 - 21 WRX, 15 - 18 STI] Axle Back Exhaust Polished Tip | 1.10204.1 - JDMuscleAxle Back Exhausts1.10204.1](http://jdmuscleusa.com/cdn/shop/files/factionfab-15-21-wrx-15-18-sti-axle-back-exhaust-polished-tip-1102041-5689418.jpg?v=1770327979&width=220)
![FactionFab [15 - 21 WRX, 15 - 18 STI] Axle Back Exhaust Polished Tip | 1.10204.1 - JDMuscleAxle Back Exhausts1.10204.1](http://jdmuscleusa.com/cdn/shop/files/factionfab-15-21-wrx-15-18-sti-axle-back-exhaust-polished-tip-1102041-1324329.jpg?v=1770327979&width=220)
![Killer B Motorsports [02 - 07 WRX, 04 - 21 STI] 3" Cast Turbo Inlet to 84mm Adapter Coupler | TIEJC84 - JDMuscleTurbo Inlet Hoses and PipesklbTIEJC84](http://jdmuscleusa.com/cdn/shop/files/killer-b-motorsports-02-07-wrx-04-21-sti-3-cast-turbo-inlet-to-84mm-adapter-coupler-tiejc84-6849084.jpg?v=1770327976&width=220)
![IAG Performance [02 - 14 WRX, 04 - 21 STI, 05 - 12 LGT, 04 - 13 FXT] 8mm Thick Phenolic Spacers | IAG - AFD - 3104 - JDMusclePhenolic Thermal Intake Manifold SpacersIAG-AFD-3104](http://jdmuscleusa.com/cdn/shop/files/iag-performance-02-14-wrx-04-21-sti-05-12-lgt-04-13-fxt-8mm-thick-phenolic-spacers-iag-afd-3104-4678295.jpg?v=1770327978&width=220)
![MBRP [15 - 21 WRX/STI] 3inch Cat Back Dual Split Rear Exit T304 with Carbon Fiber Tips Street version | S48003CF - JDMuscleCat Back Exhaust SystemMBRS48003CF](http://jdmuscleusa.com/cdn/shop/products/mbrp-15-21-wrxsti-3inch-cat-back-dual-split-rear-exit-t304-with-carbon-fiber-tips-street-version-s48003cf-1108331.jpg?v=1770329143&width=220)
![MBRP [15 - 21 WRX/STI] 3inch Cat Back Dual Split Rear Exit T304 with Carbon Fiber Tips Street version | S48003CF - JDMuscleCat Back Exhaust SystemMBRS48003CF](http://jdmuscleusa.com/cdn/shop/files/mbrp-15-21-wrxsti-3inch-cat-back-dual-split-rear-exit-t304-with-carbon-fiber-tips-street-version-s48003cf-4543361.png?v=1770329144&width=220)
![ETS [15 - 21 STI] Stock Turbo Piping Kit - JDMuscleIntercooler Piping Kits200-30-ICP-001OEM - 1.75"Stock BOVStock](http://jdmuscleusa.com/cdn/shop/products/ets-15-21-sti-stock-turbo-piping-kit-1940460.jpg?v=1770329054&width=220)
![Remark [15 - 21 WRX/STI] Stainless Steel Axle Back w/ Double Wall 4 Inch Polished Tips | RO - TSVA - D4 - JDMuscleAxle Back ExhaustsremRO-TSVA-D4](http://jdmuscleusa.com/cdn/shop/products/remark-15-21-wrxsti-stainless-steel-axle-back-w-double-wall-4-inch-polished-tips-ro-tsva-d4-3491771.jpg?v=1770329774&width=220)
![Remark [15 - 21 WRX/STI] Stainless Steel Axle Back w/ Double Wall 4 Inch Polished Tips | RO - TSVA - D4 - JDMuscleAxle Back ExhaustsremRO-TSVA-D4](http://jdmuscleusa.com/cdn/shop/files/remark-15-21-wrxsti-stainless-steel-axle-back-w-double-wall-4-inch-polished-tips-ro-tsva-d4-8083148.jpg?v=1770329774&width=220)
![Mishimoto [08 - 14 WRX / 08 - 21 STI] Silicone Radiator Hose Kit Neon Yellow | MMHOSE - STI - 08NY - JDMuscleRadiator HosesmisMMHOSE-STI-08NY](http://jdmuscleusa.com/cdn/shop/products/mishimoto-08-14-wrx-08-21-sti-silicone-radiator-hose-kit-neon-yellow-mmhose-sti-08ny-9748599.jpg?v=1770329892&width=220)
![Mishimoto [08 - 14 WRX / 08 - 21 STI] Silicone Radiator Hose Kit Neon Yellow | MMHOSE - STI - 08NY - JDMuscleRadiator HosesmisMMHOSE-STI-08NY](http://jdmuscleusa.com/cdn/shop/products/mishimoto-08-14-wrx-08-21-sti-silicone-radiator-hose-kit-neon-yellow-mmhose-sti-08ny-3106639.jpg?v=1770329892&width=220)