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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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1030 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 $499.95 7% off

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per 

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 $363.95 8% off

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

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

Diablo Sport
4.0 (1)

Regular price $787.95 $749.95 5% off

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per 

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 $499.95 7% off

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per 

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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per 

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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American Brother Designs Washer Fluid Cap Cover: 300, Challenger, Charger & Magnum 2005 - 2014
American Brother Designs Washer Fluid Cap Cover: 300, Challenger, Charger & Magnum 2005 - 2014
usa

American Brother Designs Washer Fluid Cap Cover: 300, Challenger, Charger & Magnum 2005 - 2014

American Brother Designs

Regular price $109.00 $59.00 46% off

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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)
Spec D LED Projector HeadLights (Black): Jeep Grand Cherokee 1999 - 2004
Spec D LED Projector HeadLights (Black): Jeep Grand Cherokee 1999 - 2004

Spec D LED Projector HeadLights (Black): Jeep Grand Cherokee 1999 - 2004

Spec D

Regular price $213.00 $158.00 26% off

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per 

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 $749.95 7% off

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per 

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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per 

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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per 

OMIX Locking Gas Cap: Fits Jeep Wrangler / Gladiator / Grand Cherokee (93-26)
OMIX Locking Gas Cap: Fits Jeep Wrangler / Gladiator / Grand Cherokee (93-26)

OMIX Locking Gas Cap: Fits Most Jeep (03-25)

OMIX

$48.99

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per 

Weld Solana / Gloss Black Milled | 20x9.5 | 5x127 | +0mm Offset
Body Armor 4x4 Trail Doors Front Pair: Jeep Wrangler 1997-2006
Body Armor 4x4 Trail Doors Front Pair: Jeep Wrangler 1997-2006
Artec Industries Inner C Gussets: Jeep Wrangler (93-06)
usa

Artec Industries Inner C Gussets: Jeep Wrangler (93-06)

Artec Industries

$97.89

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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 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

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per 

MagnaFlow Conv DF Exhaust: Jeep Wrangler (00-03)
MagnaFlow Conv DF Exhaust: Jeep Wrangler (00-03)
usa

MagnaFlow Conv DF Exhaust: Jeep Wrangler 00-03 4.0L/2.5L

Magnaflow

$1,049.00

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per 

Oracle 99-13 Jeep Grand Cherokee Surface Mount LED Fog Light Halo Kit - Amber
Oracle 99-13 Jeep Grand Cherokee Surface Mount LED Fog Light Halo Kit - Green
Oracle 99-13 Jeep Grand Cherokee Surface Mount LED Fog Light Halo Kit - Red
Oracle 99-04 Jeep Grand Cherokee LED Headlight Halo Kit - Blue

Oracle 99-04 Jeep Grand Cherokee LED Headlight Halo Kit - Blue

ORACLE Lighting

$258.28

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per 

Oracle 99-04 Jeep Grand Cherokee LED Fog Light Halo Kit - Green

Oracle 99-04 Jeep Grand Cherokee LED Fog Light Halo Kit - Green

ORACLE Lighting

$146.70

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per 

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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