Shop 4.0L
Spec D Crystal Headlights (Smoke): Jeep 1999 - 2004
Spec D
Regular price
$105.00
$78.00
26% off
- Unit price
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Spec D Crystal Headlights (Chrome): Jeep Grand Cherokee 1999 - 2004
Spec D
Regular price
$97.00
$72.00
26% off
- Unit price
- /per
Spec D Projector Halo Headlights (Glossy Black): Jeep Grand Cherokee 1999 - 2004
Spec D
Regular price
$198.00
$147.00
26% off
- Unit price
- /per
Spec D Crystal Headlights (Smoke, Version 2): Jeep 1999 - 2004
Spec D
Regular price
$100.00
$74.00
26% off
- Unit price
- /per
MagnaFlow Universal Catalytic Converter: Fits Chrysler / Dodge / Jeep (05-23)
Magnaflow
$1,267.00
- Unit price
- /per
MagnaFlow Direct Fit Catalytic Converter CARB (FRONT): Jeep Wrangler TJ 2000-2003 4.0L
Magnaflow
$1,159.00
- Unit price
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Fishbone Offroad Black Textured Powdercoated Front Bumper (FRONT): Jeep Wrangler (97-06)
Fishbone Offroad
$359.99
- Unit price
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Tuff Country 1.5in Coil Spring Spacers (FRONT/REAR): Jeep Grand Cherokee (93-98) / Wrangler (97-06)
Tuff Country
$67.24
- Unit price
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DFC D&S Rotor (FRONT LEFT): Jeep Wrangler (99-06)
DFC
$140.60
- Unit price
- /per
Fishbone Offroad Black Textured Powdercoat Light Bar Bracket: Jeep Wrangler 1997-2006
Fishbone Offroad
$124.99
- Unit price
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ANZO Crystal Headlights w/ Light Bar (Chrome): Jeep Grand Cherokee 1999 - 2004
ANZO
$511.00
- Unit price
- /per
Kentrol Powder Coated Footman Loop: 97-18 Jeep Wrangler TJ / JK
Kentrol
Regular price
$24.13
$22.76
6% off
- Unit price
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Kentrol Polished Silver Windshield Wiper Arms Pair: Jeep Wrangler TJ 1997-2006
Kentrol
Regular price
$97.63
$92.06
6% off
- Unit price
- /per
R1 Concepts Drilled & Slotted Brake Rotor (REAR RIGHT): Jeep Grand Cherokee 1999-2004 2.5L/4.0L
R1 Concepts
$98.80
- Unit price
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R1 Concepts Drilled & Slotted Brake Rotor (REAR LEFT): Jeep Grand Cherokee 1999-2004 2.5L / 4.0L
R1 Concepts
$98.80
- Unit price
- /per
R1 Concepts Drilled & Slotted Brake Rotor (FRONT RIGHT): Jeep Grand Cherokee 1999-2004 2.5L / 4.0L
R1 Concepts
$114.80
- Unit price
- /per
R1 Concepts Drilled & Slotted Brake Rotor (FRONT LEFT): Jeep Grand Cherokee 1999-2004 2.5L/4.0L
R1 Concepts
$114.80
- Unit price
- /per
Magnaflow Universal Catalytic Converter: Dodge Dakota (97-04) / Jeep Wrangler (97-06)
Magnaflow
$782.00
- Unit price
- /per
Artec Industries 8.8 Swap Kit w/ Truss: Jeep Wrangler 1997-2006 - 2.63 In / High Clearance
Artec Industries
$539.99
- Unit price
- /per
Artec Industries Bushings for UCA Mount: Jeep Wrangler (97-06)
Artec Industries
$54.99
- Unit price
- /per
Energy Suspension 1in Body Lift Kit: Jeep Wrangler 1994-2006
Energy Suspension
Regular price
$425.58
$283.72
33% off
- Unit price
- /per
BedRug Front 3pc BedTred Floor Kit (FRONT): Jeep Wrangler (97-06) w/ Center Console w/ Heat Shields
BedRug
$249.95
- Unit price
- /per
Edge EvoHT2 Handheld Tuner: Fits Most GM / Ford / Dodge RAM Trucks
Edge
Regular price
$518.95
$349.95
33% off
- Unit price
- /per
MagnaFlow California Grade Cat Converter: Fits Dodge / Jeep (00-06) - SS
Magnaflow
$458.00
- Unit price
- /per
DFC 4000 HybriDynamic Front Brake Pads w/ Hardware: Jeep Grand Cherokee (99-04)
DFC
$56.00
- Unit price
- /per
Magnaflow Universal Catalytic Converter: Jeep Wrangler 1997 - 1998
Magnaflow
$490.00
- Unit price
- /per
Magnaflow Stainless Steel Front Pipe Kit: Jeep Grand Cherokee (1999-2004)
Magnaflow
$423.80
- Unit price
- /per
Billetworkz Shift Knob Hoodie Scat Pack: Fits Universal up to 2in Diameter
Billetworkz
$25.00
- Unit price
- /per
Billetworkz Shift Knob Hoodie R/T: Fits Universal up to 2in Diameter
Billetworkz
$25.00
- Unit price
- /per
Artec Industries Front Axle Swap Kit: Jeep Wrangler w/ Standard Hole
Artec Industries
$659.99
- Unit price
- /per
DFC GeoSPEC Coated Brake Rotor (FRONT): Jeep Wrangler 2.0L / 2.5L (99-06)
DFC
$71.50
- Unit price
- /per
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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.