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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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PowerStop Autospecialty Brake Kit (FRONT): Jeep Grand Cherokee 1999 - 2004
PowerStop Autospecialty Brake Kit (FRONT): Jeep Grand Cherokee 1999 - 2004

PowerStop Autospecialty Brake Kit (FRONT): Jeep Grand Cherokee 1999 - 2004

PowerStop

$139.80

Unit price
per 

Stopping Power
Performance Over Stock
Dust Levels
PowerStop Semi-Coated Rotor Kit (FRONT): Jeep Grand Cherokee 1999 - 2004

PowerStop Semi-Coated Rotor Kit (FRONT): Jeep Grand Cherokee 1999 - 2004

PowerStop

$160.25

Unit price
per 

Stopping Power
Noise Level
Performance Over Stock
Dust Levels
PowerStop Z26 Extreme Street Brake Pads (FRONT): Jeep Grand Cherokee 1999 - 2004 w/ Hardware
PowerStop Z26 Extreme Street Brake Pads (FRONT): Jeep Grand Cherokee 1999 - 2004 w/ Hardware

PowerStop Z26 Extreme Street Brake Pads (FRONT): Jeep Grand Cherokee 1999 - 2004 w/ Hardware

PowerStop

$69.43

Unit price
per 

Stopping Power
Noise Level
Performance Over Stock
Dust Levels
PowerStop Z16 Evolution Ceramic Brake Pads (REAR): Jeep Grand Cherokee 1999 - 2004
PowerStop Z16 Evolution Ceramic Brake Pads (REAR): Jeep Grand Cherokee 1999 - 2004

PowerStop Z16 Evolution Ceramic Brake Pads (REAR): Jeep Grand Cherokee 1999 - 2004

PowerStop

$35.06

Unit price
per 

Stopping Power
Performance Over Stock
Dust Levels
PowerStop Semi-Coated Rotor Kit (REAR): Jeep Grand Cherokee 1993 - 1998

PowerStop Semi-Coated Rotor Kit (REAR): Jeep Grand Cherokee 1993 - 1998

PowerStop

$124.40

Unit price
per 

Stopping Power
Noise Level
Performance Over Stock
Dust Levels
DFC Rear HD Brake Pads and Hardware Kit (REAR): Jeep Grand Cherokee (99-04)

DFC Rear HD Brake Pads and Hardware Kit (REAR): Jeep Grand Cherokee (99-04)

DFC

$54.40

Unit price
per 

Stopping Power
Noise Level
Performance Over Stock
Dust Levels
DBA Street Series Standard Front Rotor: Jeep Grand Cherokee 1999-2004
DBA Street Series Standard Front Rotor: Jeep Grand Cherokee 1999-2004

DBA Street Series Standard Front Rotor: Jeep Grand Cherokee 1999-2004

DBA

Regular price $131.29 $111.09 15% off

Unit price
per 

Stopping Power
Noise Level
Performance Over Stock
Dust Levels
DBA Street Series Rear Brake Pads: Jeep Grand Cherokee 1999-2004
DBA Street Series Rear Brake Pads: Jeep Grand Cherokee 1999-2004

DBA Street Series Rear Brake Pads: Jeep Grand Cherokee 1999-2004

DBA

Regular price $77.75 $65.79 15% off

Unit price
per 

Stopping Power
Noise Level
Performance Over Stock
Dust Levels
DBA Street Series Front Brake Pads: Jeep Grand Cherokee 1999-2004
DBA Street Series Front Brake Pads: Jeep Grand Cherokee 1999-2004

DBA Street Series Front Brake Pads: Jeep Grand Cherokee 1999-2004

DBA

Regular price $77.75 $65.79 15% off

Unit price
per 

Stopping Power
Noise Level
Performance Over Stock
Dust Levels
Rock Slide Engineering Step-Slider Skid Plate: Jeep LJ 2003-2006
Rock Slide Engineering Step-Slider Skid Plate: Jeep LJ 2003-2006
usa

Rock Slide Engineering Step-Slider Skid Plate: Jeep LJ 2003-2006

Rock Slide Engineering

$549.99

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per 

Kentrol Polished Silver Grill Guard: Jeep Wrangler TJ (87-06) / YJ (87-95)
usa

Kentrol Polished Silver Grill Guard: Jeep Wrangler TJ (87-06) / YJ (87-95)

Kentrol

Regular price $248.83 $234.62 6% off

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per 

Bilstein B8 5100 Shock Absorber Front 0-2" Lift (FRONT): Jeep Wrangler TJ 1997-2006
Bilstein B8 5100 Shock Absorber Front 0-2" Lift (FRONT): Jeep Wrangler TJ 1997-2006

Bilstein B8 5100 Shock Absorber Front 0-2" Lift (FRONT): Jeep Wrangler TJ 1997-2006

Bilstein

Regular price $171.85 $123.00 28% off

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Artec Industries Rear Swap: Jeep Wrangler TJ / LJ / JT / JL
Artec Industries Rear Swap: Jeep Wrangler TJ / LJ / JT / JL
usa

Artec Industries Rear Swap: Jeep Wrangler TJ / LJ / JT / JL

Artec Industries

$299.99

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per 

Rancho RS5000X Rear Shock: Jeep Grand Cherokee 1999-2004
Rancho RS5000X Rear Shock: Jeep Grand Cherokee 1999-2004
Diode Dynamics SL2 Pro LED Bulbs: Multiple Diode Dynamics Fitments - White
Diode Dynamics SL2 Pro LED Bulbs: Multiple Diode Dynamics Fitments - White
usa
Rugged Ridge Paracord Grab Handles Pair - Black/Black
Rugged Ridge Paracord Grab Handles Pair - Black/Black

Rugged Ridge Paracord Grab Handles Pair - Black/Black

Rugged Ridge

$59.99

Unit price
per 

Diode Dynamics SL2 LED Bulbs: Multiple White Fitments
Diode Dynamics SL2 LED Bulbs: Multiple White Fitments
usa

Diode Dynamics SL2 LED Bulbs: Multiple White Fitments

Diode Dynamics

$159.95

Unit price
per 

Air Lift Wireless Air Control System V2 w/ EZ Mount
Air Lift Wireless Air Control System V2 w/ EZ Mount

Air Lift Wireless Air Control System V2 w/ EZ Mount

Air Lift

$936.99

Unit price
per 

Air Lift Heavy Duty Compressor: Fits Most Models
Air Lift Heavy Duty Compressor: Fits Most Models

Air Lift Heavy Duty Compressor: Fits Most Models

Air Lift

$407.99

Unit price
per 

Air Lift Heavy Duty Dual Load Controller Compressor: Fits Most Models
Air Lift Heavy Duty Dual Load Controller Compressor: Fits Most Models
Spec D Crystal Headlights (Chrome, Version 2): Jeep Grand Cherokee 1999 - 2004
Spec D Crystal Headlights (Chrome, Version 2): Jeep Grand Cherokee 1999 - 2004

Spec D Crystal Headlights (Chrome, Version 2): Jeep Grand Cherokee 1999 - 2004

Spec D

Regular price $109.00 $81.00 26% off

Unit price
per 

Spec D Side Mirrors (Round, Quick Release): Jeep Wrangler 1997 - 2018
Spec D Side Mirrors (Round, Quick Release): Jeep Wrangler 1997 - 2018

Spec D Side Mirrors (Round, Quick Release): Jeep Wrangler 1997 - 2018

Spec D

Regular price $46.00 $34.00 26% off

Unit price
per 

Spec D Side Marker Lights (Amber): Jeep 1997 - 2006

Spec D

Regular price $20.00 $15.00 25% off

Unit price
per 

Spec D Corner Lights (Black): Jeep Grand Cherokee 1993 - 1998
Spec D Corner Lights (Black): Jeep Grand Cherokee 1993 - 1998

Spec D Corner Lights (Black): Jeep Grand Cherokee 1993 - 1998

Spec D

Regular price $30.00 $22.00 27% off

Unit price
per 

Spec D Crystal Headlights (Black): Jeep Grand Cherokee 1993 - 1998
Spec D Crystal Headlights (Black): Jeep Grand Cherokee 1993 - 1998

Spec D Crystal Headlights (Black): Jeep Grand Cherokee 1993 - 1998

Spec D

Regular price $146.00 $108.00 26% off

Unit price
per 

Spec D Crystal Headlights (Smoke): Jeep Grand Cherokee 1993 - 1998
Spec D Crystal Headlights (Smoke): Jeep Grand Cherokee 1993 - 1998

Spec D Crystal Headlights (Smoke): Jeep Grand Cherokee 1993 - 1998

Spec D

Regular price $139.00 $103.00 26% off

Unit price
per 

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

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

Spec D

Regular price $219.00 $162.00 26% off

Unit price
per 

Spec D Crystal Headlights (Black, Version 2): Jeep Grand Cherokee 1999 - 2004
Spec D Crystal Headlights (Black, Version 2): Jeep Grand Cherokee 1999 - 2004

Spec D Crystal Headlights (Black, Version 2): Jeep Grand Cherokee 1999 - 2004

Spec D

Regular price $128.00 $95.00 26% off

Unit price
per 

Spec D Corner Lights (Chrome): Jeep Grand Cherokee 1993 - 1998
Spec D Corner Lights (Chrome): Jeep Grand Cherokee 1993 - 1998

Spec D Corner Lights (Chrome): Jeep Grand Cherokee 1993 - 1998

Spec D

Regular price $30.00 $22.00 27% off

Unit price
per 

Spec D Side Marker Lights (Amber): Jeep Wrangler TJ 1997 - 2006
Spec D Side Marker Lights (Amber): Jeep Wrangler TJ 1997 - 2006

Spec D Side Marker Lights (Amber): Jeep Wrangler TJ 1997 - 2006

Spec D

Regular price $20.00 $15.00 25% off

Unit price
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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