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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![MBRP [15 - 21 WRX 2.0L/STI 2.5L] 2.5in Dual Split Rear Exit w/ 3.5" CF Tips - T304 | S48013CF - JDMuscleAxle Back ExhaustsmbrpS48013CF](//jdmuscleusa.com/cdn/shop/products/mbrp-15-21-wrx-20lsti-25l-25in-dual-split-rear-exit-w-35-cf-tips-t304-s48013cf-9483336.jpg?v=1770327579&width=220)
![MBRP [15 - 21 WRX 2.0L/STI 2.5L] 2.5in Dual Split Rear Exit w/ 3.5" CF Tips - T304 | S48013CF - JDMuscleAxle Back ExhaustsmbrpS48013CF](//jdmuscleusa.com/cdn/shop/products/mbrp-15-21-wrx-20lsti-25l-25in-dual-split-rear-exit-w-35-cf-tips-t304-s48013cf-5413636.jpg?v=1770327580&width=220)
Up to $118.82 off
In StockMBRP 2.5in Dual Split Rear Exit w/ 3.5" CF Tips - T304
Fits: 15-21 WRX 2.0L/STI 2.5L
Only 6 leftRegular price $504.99Sale price $504.99 Regular priceUnit price per$623.81 -
DELICIOUS TUNING 08+ SUBARU MAF EXTENSION | DT_MAF-V2_EXT
Regular price $35.00Sale price $35.00 Regular priceUnit price per$35.00 -
![MBRP [15 - 21 WRX 2.0L/STI 2.5L] 3in Dual Split Rear Exit w/ 3.5" CF Tips - T304 - Race Version | S48023CF - JDMuscleCat Back Exhaust SystemmbrpS48023CF](//jdmuscleusa.com/cdn/shop/products/mbrp-15-21-wrx-20lsti-25l-3in-dual-split-rear-exit-w-35-cf-tips-t304-race-version-s48023cf-4297883.jpg?v=1770327576&width=220)
![MBRP [15 - 21 WRX 2.0L/STI 2.5L] 3in Dual Split Rear Exit w/ 3.5" CF Tips - T304 - Race Version | S48023CF - JDMuscleCat Back Exhaust SystemmbrpS48023CF](//jdmuscleusa.com/cdn/shop/products/mbrp-15-21-wrx-20lsti-25l-3in-dual-split-rear-exit-w-35-cf-tips-t304-race-version-s48023cf-1983610.jpg?v=1770327576&width=220)
Up to $247.06 off
In StockMBRP 3in Dual Split Rear Exit w/ 3.5" CF Tips - T304 - Race Version | S48023CF
Fits: 15-21 WRX 2.0L/STI 2.5L
Only 13 leftRegular price $1,049.99Sale price $1,049.99 Regular priceUnit price per$1,297.05 -
![Perrin [15 - 21 WRX/STI] Radiator Shroud Without OEM Intake Scoop - Neon Yellow | PSP - ENG - 512 - 2NY - JDMuscleRadiator ShroudsperPSP-ENG-512-2NY](//jdmuscleusa.com/cdn/shop/products/perrin-15-21-wrxsti-radiator-shroud-without-oem-intake-scoop-neon-yellow-psp-eng-512-2ny-2248735.jpg?v=1770327578&width=220)
![Perrin [15 - 21 WRX/STI] Radiator Shroud Without OEM Intake Scoop - Neon Yellow | PSP - ENG - 512 - 2NY - JDMuscleRadiator ShroudsperPSP-ENG-512-2NY](//jdmuscleusa.com/cdn/shop/products/perrin-15-21-wrxsti-radiator-shroud-without-oem-intake-scoop-neon-yellow-psp-eng-512-2ny-9737858.jpg?v=1770327579&width=220)
Up to $36.25 off
In StockPerrin Radiator Shroud Without OEM Intake Scoop - Neon Yellow | PSP-ENG-512-2NY
Fits: 15-21 WRX/STI
Only 11 leftRegular price $108.75Sale price $108.75 Regular priceUnit price per$145.00 -
Up to $20 off
In StockTomei High Performance Valve Spring Set Turbo Models
Fits: 02-14 WRX, 04-21 STI, 05-12 LGT, 04-13 FXT
Only 5 leftRegular price $180.00Sale price $180.00 Regular priceUnit price per$200.00 -
IAG 06-14 WRX, 04-21 STI Air / Oil Separator | AOS Competition to Street Series Conversion Kit | IAG-ENG-7113
Regular price $104.99Sale price $104.99 Regular priceUnit price per$104.99 -
IAG 08-14 WRX / 08-20 STI / 05-09 LGT AOS Replacement Harness Relocation Bracket | IAG-RPL-7151HR
Regular price $14.99Sale price $14.99 Regular priceUnit price per$14.99 -
![Gates [04 - 14 WRX, 04 - 21 STI] Racing Timing Belt Kit | TCK328RB - JDMuscleTiming Belt ComponentsTCK328RB](//jdmuscleusa.com/cdn/shop/files/gates-04-14-wrx-04-21-sti-racing-timing-belt-kit-tck328rb-4786491.jpg?v=1770327639&width=220)
Up to $1,363.03 offGates Racing Timing Belt Kit | TCK328RB
Fits: 04-14 WRX, 04-21 STI
Regular price $470.00Sale price $470.00 Regular priceUnit price per$1,833.03 -
IAG Performance MAF Sensor Block Off Plate Silver
Fits: 08-14 WRX, 08-21 STI, 05-09 LGT
Regular price $41.99Sale price $41.99 Regular priceUnit price per$41.99 -
![Cusco [02 - 14 WRX, 04 - 21 STI, 05 - 09 LGT] Aluminum Pulley Set | 6A1 - 733 - A - JDMusclePulleyscus6A1-733-A](//jdmuscleusa.com/cdn/shop/files/cusco-02-14-wrx-04-21-sti-05-09-lgt-aluminum-pulley-set-6a1-733-a-6902588.jpg?v=1770327688&width=220)
![Cusco [02 - 14 WRX, 04 - 21 STI, 05 - 09 LGT] Aluminum Pulley Set | 6A1 - 733 - A - JDMusclePulleyscus6A1-733-A](//jdmuscleusa.com/cdn/shop/files/cusco-02-14-wrx-04-21-sti-05-09-lgt-aluminum-pulley-set-6a1-733-a-2260376.jpg?v=1770327688&width=220)
Up to $54 offCusco Aluminum Pulley Set | 6A1-733-A
Fits: 02-14 WRX, 04-21 STI, 05-09 LGT
Regular price $486.00Sale price $486.00 Regular priceUnit price per$540.00 -
Up to $15.25 off
In StockPerrin 06-14 WRX / 07-21 STI / 12-16 Impreza / 06-13 FXT / 05-09 Legacy Alternator Pulley Blue | PSP-ENG-119BL
Only 3 leftRegular price $45.75Sale price $45.75 Regular priceUnit price per$61.00 -
![Nameless Performance [11 - 21 WRX Sedan, 11 - 21 STI Sedan] Axle Back Polished Tips and No Muffler for Invidia Q300 / R400 Catback Exhaust Systems | SUAB15STI - INV - 35SSW - JDMuscleAxle Back ExhaustsSUAB15STI-INV-35SSW](//jdmuscleusa.com/cdn/shop/files/nameless-performance-11-21-wrx-sedan-11-21-sti-sedan-axle-back-polished-tips-and-no-muffler-for-invidia-q300-r400-catback-exhaust-systems-suab15sti-inv-35ssw-3762911.jpg?v=1770327808&width=220)
![Nameless Performance [11 - 21 WRX Sedan, 11 - 21 STI Sedan] Axle Back Polished Tips and No Muffler for Invidia Q300 / R400 Catback Exhaust Systems | SUAB15STI - INV - 35SSW - JDMuscleAxle Back ExhaustsSUAB15STI-INV-35SSW](//jdmuscleusa.com/cdn/shop/files/nameless-performance-11-21-wrx-sedan-11-21-sti-sedan-axle-back-polished-tips-and-no-muffler-for-invidia-q300-r400-catback-exhaust-systems-suab15sti-inv-35ssw-3096433.jpg?v=1770327809&width=220)
Nameless Performance Axle Back Polished Tips and No Muffler for Invidia Q300 / R400 Catback Exhaust Systems
Fits: 11-21 WRX Sedan, 11-21 STI Sedan
Regular price $730.00Sale price $730.00 Regular priceUnit price per$0.00 -
Verus Engineering 15-21 STI Air Oil Separator - Black | A0323A-BLK
Regular price $428.95Sale price $428.95 Regular priceUnit price per$428.95 -
![Nameless Performance [15 - 21 WRX, 15 - 18 STI] Axle Back Exhaust w/ 3" Double Wall Polished Tips and 4" Mufflers | SUAB15WRX - 4MU - 30SDW - JDMuscleAxle Back ExhaustsSUAB15WRX-4MU-30SDW](//jdmuscleusa.com/cdn/shop/files/nameless-performance-15-21-wrx-15-18-sti-axle-back-exhaust-w-3-double-wall-polished-tips-and-4-mufflers-suab15wrx-4mu-30sdw-6518727.jpg?v=1770327864&width=220)
![Nameless Performance [15 - 21 WRX, 15 - 18 STI] Axle Back 3.5" Single Wall Polished Tips and No Muffler | SUAB15WRX - 0MU - 35SSW - JDMuscleAxle Back ExhaustsSUAB15WRX-0MU-35SSW](//jdmuscleusa.com/cdn/shop/files/nameless-performance-15-21-wrx-15-18-sti-axle-back-35-single-wall-polished-tips-and-no-muffler-suab15wrx-0mu-35ssw-1129950.jpg?v=1770327693&width=220)
Nameless Performance Axle Back Exhaust w/ 3" Double Wall Polished Tips and 4" Mufflers
Fits: 15-21 WRX, 15-18 STI
Regular price $880.00Sale price $880.00 Regular priceUnit price per$0.00 -
![COBB [15 - 21 STI] NexGen Stage 2 to Stage 2 + Flex Fuel Power Package Upgrade - JDMuscleEngine Management SensorscobbNEXGENFF001](//jdmuscleusa.com/cdn/shop/files/cobb-15-21-sti-nexgen-stage-2-to-stage-2-flex-fuel-power-package-upgrade-3710940.jpg?v=1770327866&width=220)
![COBB [15 - 21 STI] NexGen Stage 2 to Stage 2 + Flex Fuel Power Package Upgrade - JDMuscleEngine Management SensorscobbNEXGENFF001](//jdmuscleusa.com/cdn/shop/files/cobb-15-21-sti-nexgen-stage-2-to-stage-2-flex-fuel-power-package-upgrade-3113632.jpg?v=1770327866&width=220)
Up to $8 offCOBB NexGen Stage 2 to Stage 2 + Flex Fuel Power Package Upgrade
Fits: 15-21 STI
Regular price $972.00Sale price $972.00 Regular priceUnit price per$980.00 -
![COBB [15 - 21 STI] Previous Ethanol Sensor to NexGen Fuel Ethanol Sensor Kit - Module + Harness Only - JDMuscleEngine Management Sensorscobb315670](//jdmuscleusa.com/cdn/shop/files/cobb-15-21-sti-previous-ethanol-sensor-to-nexgen-fuel-ethanol-sensor-kit-module-harness-only-9461054.jpg?v=1770327867&width=220)
![COBB [15 - 21 STI] Previous Ethanol Sensor to NexGen Fuel Ethanol Sensor Kit - Module + Harness Only - JDMuscleEngine Management Sensorscobb315670](//jdmuscleusa.com/cdn/shop/files/cobb-15-21-sti-previous-ethanol-sensor-to-nexgen-fuel-ethanol-sensor-kit-module-harness-only-8251517.jpg?v=1770327867&width=220)
In StockCOBB Previous Ethanol Sensor to NexGen Fuel Ethanol Sensor Kit - Module + Harness Only
Fits: 15-21 STI
Only 10 leftRegular price $540.00Sale price $540.00 Regular priceUnit price per$540.00
![MBRP [15 - 21 WRX 2.0L/STI 2.5L] 2.5in Dual Split Rear Exit w/ 3.5" CF Tips - T304 | S48013CF - JDMuscleAxle Back ExhaustsmbrpS48013CF](http://jdmuscleusa.com/cdn/shop/products/mbrp-15-21-wrx-20lsti-25l-25in-dual-split-rear-exit-w-35-cf-tips-t304-s48013cf-9483336.jpg?v=1770327579&width=220)
![MBRP [15 - 21 WRX 2.0L/STI 2.5L] 2.5in Dual Split Rear Exit w/ 3.5" CF Tips - T304 | S48013CF - JDMuscleAxle Back ExhaustsmbrpS48013CF](http://jdmuscleusa.com/cdn/shop/products/mbrp-15-21-wrx-20lsti-25l-25in-dual-split-rear-exit-w-35-cf-tips-t304-s48013cf-5413636.jpg?v=1770327580&width=220)
![MBRP [15 - 21 WRX 2.0L/STI 2.5L] 3in Dual Split Rear Exit w/ 3.5" CF Tips - T304 - Race Version | S48023CF - JDMuscleCat Back Exhaust SystemmbrpS48023CF](http://jdmuscleusa.com/cdn/shop/products/mbrp-15-21-wrx-20lsti-25l-3in-dual-split-rear-exit-w-35-cf-tips-t304-race-version-s48023cf-4297883.jpg?v=1770327576&width=220)
![MBRP [15 - 21 WRX 2.0L/STI 2.5L] 3in Dual Split Rear Exit w/ 3.5" CF Tips - T304 - Race Version | S48023CF - JDMuscleCat Back Exhaust SystemmbrpS48023CF](http://jdmuscleusa.com/cdn/shop/products/mbrp-15-21-wrx-20lsti-25l-3in-dual-split-rear-exit-w-35-cf-tips-t304-race-version-s48023cf-1983610.jpg?v=1770327576&width=220)
![Perrin [15 - 21 WRX/STI] Radiator Shroud Without OEM Intake Scoop - Neon Yellow | PSP - ENG - 512 - 2NY - JDMuscleRadiator ShroudsperPSP-ENG-512-2NY](http://jdmuscleusa.com/cdn/shop/products/perrin-15-21-wrxsti-radiator-shroud-without-oem-intake-scoop-neon-yellow-psp-eng-512-2ny-2248735.jpg?v=1770327578&width=220)
![Perrin [15 - 21 WRX/STI] Radiator Shroud Without OEM Intake Scoop - Neon Yellow | PSP - ENG - 512 - 2NY - JDMuscleRadiator ShroudsperPSP-ENG-512-2NY](http://jdmuscleusa.com/cdn/shop/products/perrin-15-21-wrxsti-radiator-shroud-without-oem-intake-scoop-neon-yellow-psp-eng-512-2ny-9737858.jpg?v=1770327579&width=220)
![Gates [04 - 14 WRX, 04 - 21 STI] Racing Timing Belt Kit | TCK328RB - JDMuscleTiming Belt ComponentsTCK328RB](http://jdmuscleusa.com/cdn/shop/files/gates-04-14-wrx-04-21-sti-racing-timing-belt-kit-tck328rb-4786491.jpg?v=1770327639&width=220)
![Cusco [02 - 14 WRX, 04 - 21 STI, 05 - 09 LGT] Aluminum Pulley Set | 6A1 - 733 - A - JDMusclePulleyscus6A1-733-A](http://jdmuscleusa.com/cdn/shop/files/cusco-02-14-wrx-04-21-sti-05-09-lgt-aluminum-pulley-set-6a1-733-a-6902588.jpg?v=1770327688&width=220)
![Cusco [02 - 14 WRX, 04 - 21 STI, 05 - 09 LGT] Aluminum Pulley Set | 6A1 - 733 - A - JDMusclePulleyscus6A1-733-A](http://jdmuscleusa.com/cdn/shop/files/cusco-02-14-wrx-04-21-sti-05-09-lgt-aluminum-pulley-set-6a1-733-a-2260376.jpg?v=1770327688&width=220)
![Nameless Performance [11 - 21 WRX Sedan, 11 - 21 STI Sedan] Axle Back Polished Tips and No Muffler for Invidia Q300 / R400 Catback Exhaust Systems | SUAB15STI - INV - 35SSW - JDMuscleAxle Back ExhaustsSUAB15STI-INV-35SSW](http://jdmuscleusa.com/cdn/shop/files/nameless-performance-11-21-wrx-sedan-11-21-sti-sedan-axle-back-polished-tips-and-no-muffler-for-invidia-q300-r400-catback-exhaust-systems-suab15sti-inv-35ssw-3762911.jpg?v=1770327808&width=220)
![Nameless Performance [11 - 21 WRX Sedan, 11 - 21 STI Sedan] Axle Back Polished Tips and No Muffler for Invidia Q300 / R400 Catback Exhaust Systems | SUAB15STI - INV - 35SSW - JDMuscleAxle Back ExhaustsSUAB15STI-INV-35SSW](http://jdmuscleusa.com/cdn/shop/files/nameless-performance-11-21-wrx-sedan-11-21-sti-sedan-axle-back-polished-tips-and-no-muffler-for-invidia-q300-r400-catback-exhaust-systems-suab15sti-inv-35ssw-3096433.jpg?v=1770327809&width=220)
![Nameless Performance [15 - 21 WRX, 15 - 18 STI] Axle Back Exhaust w/ 3" Double Wall Polished Tips and 4" Mufflers | SUAB15WRX - 4MU - 30SDW - JDMuscleAxle Back ExhaustsSUAB15WRX-4MU-30SDW](http://jdmuscleusa.com/cdn/shop/files/nameless-performance-15-21-wrx-15-18-sti-axle-back-exhaust-w-3-double-wall-polished-tips-and-4-mufflers-suab15wrx-4mu-30sdw-6518727.jpg?v=1770327864&width=220)
![Nameless Performance [15 - 21 WRX, 15 - 18 STI] Axle Back 3.5" Single Wall Polished Tips and No Muffler | SUAB15WRX - 0MU - 35SSW - JDMuscleAxle Back ExhaustsSUAB15WRX-0MU-35SSW](http://jdmuscleusa.com/cdn/shop/files/nameless-performance-15-21-wrx-15-18-sti-axle-back-35-single-wall-polished-tips-and-no-muffler-suab15wrx-0mu-35ssw-1129950.jpg?v=1770327693&width=220)
![COBB [15 - 21 STI] NexGen Stage 2 to Stage 2 + Flex Fuel Power Package Upgrade - JDMuscleEngine Management SensorscobbNEXGENFF001](http://jdmuscleusa.com/cdn/shop/files/cobb-15-21-sti-nexgen-stage-2-to-stage-2-flex-fuel-power-package-upgrade-3710940.jpg?v=1770327866&width=220)
![COBB [15 - 21 STI] NexGen Stage 2 to Stage 2 + Flex Fuel Power Package Upgrade - JDMuscleEngine Management SensorscobbNEXGENFF001](http://jdmuscleusa.com/cdn/shop/files/cobb-15-21-sti-nexgen-stage-2-to-stage-2-flex-fuel-power-package-upgrade-3113632.jpg?v=1770327866&width=220)
![COBB [15 - 21 STI] Previous Ethanol Sensor to NexGen Fuel Ethanol Sensor Kit - Module + Harness Only - JDMuscleEngine Management Sensorscobb315670](http://jdmuscleusa.com/cdn/shop/files/cobb-15-21-sti-previous-ethanol-sensor-to-nexgen-fuel-ethanol-sensor-kit-module-harness-only-9461054.jpg?v=1770327867&width=220)
![COBB [15 - 21 STI] Previous Ethanol Sensor to NexGen Fuel Ethanol Sensor Kit - Module + Harness Only - JDMuscleEngine Management Sensorscobb315670](http://jdmuscleusa.com/cdn/shop/files/cobb-15-21-sti-previous-ethanol-sensor-to-nexgen-fuel-ethanol-sensor-kit-module-harness-only-8251517.jpg?v=1770327867&width=220)