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Shop 4.0L

Upgrade Your 4.0L Engine with FastHemis The 4.0L inline-six engine is known for its durability and smooth power delivery, commonly found in Jeep models like the Wrangler and Cherokee. Its robust design offers a solid foundation for both daily driving reliability and moderate performance enhancements. At FastHemis, you'll find a range of parts tailored to the 4.0L platform, including intake and exhaust upgrades, ignition components, and tuning accessories. These parts help improve throttle response, efficiency, and overall engine capability without compromising the engine’s legendary reliability. Key upgrades for your 4.0L engine include: - High-flow air intake systems - Performance exhaust components - Ignition and spark upgrades - Engine management and tuning tools Shop 4.0L engine upgrades at FastHemis.
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1006 Results

DiabloSport inTune i3 Platinum Programmer: Jeep Grand Cherokee / Wrangler / Commander 2005 - 2014

DiabloSport inTune i3 Platinum Programmer: Jeep Grand Cherokee / Wrangler / Commander 2005 - 2014

Diablo Sport
4.5 (2)

Regular price $535.95 $475.95 11% off

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American Brother Designs Washer Fluid Cap Cover: Chrysler, Dodge, Jeep & Ram 2005 - 2025
American Brother Designs Washer Fluid Cap Cover: Chrysler, Dodge, Jeep & Ram 2005 - 2025
usa

American Brother Designs Washer Fluid Cap Cover: Chrysler, Dodge, Jeep & Ram 2005 - 2025

American Brother Designs

Regular price $109.00 $59.00 46% off

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American Brother Designs Radiator Cap Cover: Chrysler, Dodge, Jeep & Ram 2005 - 2025
American Brother Designs Radiator Cap Cover: Chrysler, Dodge, Jeep & Ram 2005 - 2025
usa

American Brother Designs Radiator Cap Cover: Chrysler, Dodge, Jeep & Ram 2005 - 2025

American Brother Designs
5.0 (1)

Regular price $109.00 $59.00 46% off

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per 

American Brother Designs Coolant Reservoir Cap Cover: Chrysler, Dodge, Jeep & Ram 2005 - 2025
American Brother Designs Coolant Reservoir Cap Cover: Chrysler, Dodge, Jeep & Ram 2005 - 2025
usa

American Brother Designs Coolant Reservoir Cap Cover: Chrysler, Dodge, Jeep & Ram 2005 - 2025

American Brother Designs

Regular price $109.00 $59.00 46% off

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Flowmaster FloxFX Exhaust System: Jeep Grand Cherokee 4.0L / 4.7L 1999 - 2004
Flowmaster FloxFX Exhaust System: Jeep Grand Cherokee 4.0L / 4.7L 1999 - 2004
usa

Flowmaster FloxFX Exhaust System: Jeep Grand Cherokee 4.0L / 4.7L 1999 - 2004

Flowmaster
5.0 (2)

Regular price $393.95 $314.95 20% off

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Amerihood AAG Functional Ram Air Hood: Jeep Wrangler TJ 1997 - 2006
Amerihood AAG Functional Ram Air Hood: Jeep Wrangler TJ 1997 - 2006

Amerihood AAG Functional Ram Air Hood: Jeep Wrangler TJ 1997 - 2006

Amerihood

Regular price $986.00 $655.00 34% off

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DiabloSport inTune i3 Programmer: Jeep Grand Cherokee / Wrangler / Commander 2005 - 2014
DiabloSport inTune i3 Programmer: Jeep Grand Cherokee / Wrangler / Commander 2005 - 2014

DiabloSport inTune i3 Programmer: Jeep Grand Cherokee / Wrangler / Commander 2005 - 2014

Diablo Sport

Regular price $535.95 $475.95 11% off

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per 

Ripp Hi-Perf Coil Pack Kit w/ Spark Plug Wires & NGK Plugs: Jeep Grand Cherokee 4.0L (99-04)
Ripp Hi-Perf Coil Pack Kit w/ Spark Plug Wires & NGK Plugs: Jeep Grand Cherokee 4.0L (99-04)
DiabloSport Trinity 2 (T2 EX) Programmer / Monitor: Jeep Vehicles 2005 - 2014
DiabloSport Trinity 2 (T2 EX) Programmer / Monitor: Jeep Vehicles 2005 - 2014

DiabloSport Trinity 2 (T2 EX) Programmer / Monitor: Jeep Vehicles 2005 - 2014

Diablo Sport

Regular price $806.95 $716.95 11% off

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Spec D Projector Halo Headlights (Smoke): Jeep Grand Cherokee 1999 - 2004
Spec D Projector Halo Headlights (Smoke): Jeep Grand Cherokee 1999 - 2004

Spec D Projector Halo Headlights (Smoke): Jeep Grand Cherokee 1999 - 2004

Spec D

Regular price $217.00 $161.00 26% off

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Spec D Aluminum Radiator: Jeep Grand Cherokee 4.0L w/ Automatic Transmission 1999 - 2004
Spec D Aluminum Radiator: Jeep Grand Cherokee 4.0L w/ Automatic Transmission 1999 - 2004

Spec D Aluminum Radiator: Jeep Grand Cherokee 4.0L w/ Automatic Transmission 1999 - 2004

Spec D

Regular price $274.00 $203.00 26% off

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Weld Solana / Gloss Black Milled | 20x9.5 | 5x127 | +0mm Offset
Amerihood GTR Functional Ram Air Hood: Jeep Grand Cherokee 1999 - 2004
Amerihood GTR Functional Ram Air Hood: Jeep Grand Cherokee 1999 - 2004

Amerihood GTR Functional Ram Air Hood: Jeep Grand Cherokee 1999 - 2004

Amerihood

Regular price $687.46 $530.68 23% off

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Odyssey Battery HD Extreme AGM Battery: Fits Jeep / Dodge / Ram (99-11)
Odyssey Battery HD Extreme AGM Battery: Fits Jeep / Dodge / Ram (99-11)
usa

Odyssey Battery HD Extreme AGM Battery: Fits Jeep / Dodge / Ram (99-11)

Odyssey Battery

Regular price $488.12 $436.99 10% off

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Edge A-Pillar Display Mount: Fits Most Trucks w/ Hardware

Edge A-Pillar Display Mount: Fits Most Trucks w/ Hardware

Edge

Regular price $71.95 $63.45 12% off

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per 

Liqui Moly Top Tec 6600 Motor Oil: Fits Most Models
Liqui Moly Top Tec 6600 Motor Oil: Fits Most Models

Liqui Moly Top Tec 6600 Motor Oil: Fits Most Models

LIQUI MOLY

$89.70

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per 

Liqui Moly Pro-Line Engine Flush: Fits Most Models
Liqui Moly Pro-Line Engine Flush: Fits Most Models

Liqui Moly Pro-Line Engine Flush: Fits Most Models

LIQUI MOLY

$185.70

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per 

Liqui Moly Top Tec 6600 Motor Oil: Fits Most Models
Liqui Moly Top Tec 6600 Motor Oil: Fits Most Models

Liqui Moly Top Tec 6600 Motor Oil: Fits Most Models

LIQUI MOLY

$270.95

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per 

Raxiom Gladiator LED Tail Lights (REAR): Jeep Wrangler 1997-06
Raxiom Gladiator LED Tail Lights (REAR): Jeep Wrangler 1997-06
Liqui Moly Top Tec 6200 Motor Oil: Fits Most Models
Liqui Moly Top Tec 6200 Motor Oil: Fits Most Models

Liqui Moly Top Tec 6200 Motor Oil: Fits Most Models

LIQUI MOLY

$311.80

Unit price
per 

Liqui Moly Top Tec 6200 Motor Oil: Fits Most Models

Liqui Moly Top Tec 6200 Motor Oil: Fits Most Models

LIQUI MOLY

$297.95

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per 

JKS Adjustable Rear Track Bar (REAR): Jeep Grand Cherokee (93-98)
JKS Adjustable Rear Track Bar (REAR): Jeep Grand Cherokee (93-98)

JKS Adjustable Rear Track Bar (REAR): Jeep Grand Cherokee (93-98)

JKS Manufacturing

$170.95

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per 

Energy Suspension Black Rear Control Arm Bushings: Jeep Wrangler 1997-2006 w/ OEM Outer Shells
Energy Suspension Black Rear Control Arm Bushings: Jeep Wrangler 1997-2006 w/ OEM Outer Shells
usa

Energy Suspension Black Rear Control Arm Bushings: Jeep Wrangler 1997-2006 w/ OEM Outer Shells

Energy Suspension

Regular price $189.01 $126.01 33% off

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Method Wheels 709-HD / Matte Black | 18x9 | 5x5 | 12/5.5"
Method Wheels 709-HD / Matte Black | 18x9 | 5x5 | 12/5.5"

Method Wheels 709-HD / Matte Black | 18x9 | 5x5 | 12/5.5"

Method Wheels

$449.00

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Performance Upgrades for Your 4.0L Inline-Six Engine

The 4.0L inline-six engine is a durable and smooth-running powerplant widely recognized in Jeep Wrangler and Cherokee models. Known for its reliability and balanced power delivery, this engine offers a solid base for bolt-on performance enhancements that improve throttle response and efficiency without sacrificing longevity.

Key Performance Upgrades for the 4.0L Engine

Enhancing your 4.0L engine focuses on improving airflow, ignition, and engine management to unlock better throttle response and overall drivability. Popular upgrades include high-flow intake systems that increase air volume, performance exhaust components that reduce backpressure, and ignition upgrades that ensure stronger, more consistent sparks.

  • High-flow air intake systems to boost airflow and efficiency
  • Performance exhaust components for improved scavenging and sound
  • Ignition and spark upgrades to optimize combustion
  • Engine management and tuning tools for precise calibration

How to Maintain Reliability While Upgrading Your 4.0L

The 4.0L engine’s reputation for durability means upgrades should complement its robust design without over-stressing components. Focus on bolt-on parts that enhance performance within the engine’s mechanical limits. Proper tuning and quality parts help maintain reliability while extracting more capability from your engine.

Find the Right 4.0L Engine Parts at FastHemis

At FastHemis, we offer a curated selection of 4.0L engine upgrades designed to improve performance and maintain reliability. Whether you’re looking for intake kits, exhaust solutions, ignition components, or tuning accessories, our parts are fitment-focused and engineered for your Jeep’s inline-six. Shop the 4.0L collection today to enhance your engine’s capability.

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