Shop 4.0L
DiabloSport inTune i3 Platinum Programmer: Jeep Grand Cherokee / Wrangler / Commander 2005-2014
Diablo Sport
Regular price
$535.95
$499.95
7% off
- Unit price
- /per
Flowmaster FloxFX Exhaust System: Jeep Grand Cherokee 4.0L / 4.7L 1999 - 2004
Flowmaster
Regular price
$393.95
$363.95
8% off
- Unit price
- /per
DiabloSport Trinity 2 EX Platinum Programmer / Monitor: Jeep 2005-2014
Diablo Sport
Regular price
$787.95
$749.95
5% off
- Unit price
- /per
Diablo Sport inTune i3 Programmer: Jeep Grand Cherokee / Wrangler / Commander 2005-2014 5.7L Hemi / 4.0L I6
Diablo Sport
Regular price
$535.95
$499.95
7% off
- Unit price
- /per
Amerihood AAG Functional Ram Air Hood: Jeep Wrangler TJ 1997 - 2006
Amerihood
Regular price
$986.00
$655.00
34% off
- Unit price
- /per
Ripp Hi-Perf Coil Pack Kit w/ Spark Plug Wires & NGK Plugs: Jeep Grand Cherokee 4.0L (99-04)
Ripp
Regular price from $299.00 Up to 13% off
- Unit price
- /per
Edge Digital Monitor Insight CTS3: Fits Most Domestic Gas and Diesel Trucks 1996-2024 w/ Windshield Mounting Bracket
Edge
Regular price
$575.95
$549.95
5% off
- Unit price
- /per
Amerihood GTR Functional Ram Air Hood: Jeep Grand Cherokee 1999 - 2004
Amerihood
Regular price
$687.46
$530.68
23% off
- Unit price
- /per
American Brother Designs Washer Fluid Cap Cover: 300, Challenger, Charger & Magnum 2005 - 2014
American Brother Designs
Regular price
$109.00
$59.00
46% off
- Unit price
- /per
Spec D LED Projector HeadLights (Black): Jeep Grand Cherokee 1999 - 2004
Spec D
Regular price
$213.00
$158.00
26% off
- Unit price
- /per
DiabloSport Trinity 2 EX Programmer / Monitor: Jeep 2005-2014
Diablo Sport
Regular price
$806.95
$749.95
7% off
- Unit price
- /per
MagnaFlow BRE Direct-Fit Aluminized Steel Exhaust Kit: Jeep Grand Cherokee 99-04
Magnaflow
$238.00
- Unit price
- /per
Spec D Projector Halo Headlights (Smoke): Jeep Grand Cherokee 1999 - 2004
Spec D
Regular price
$217.00
$161.00
26% off
- Unit price
- /per
Spec D Aluminum Radiator: Jeep Grand Cherokee 4.0L w/ Automatic Transmission 1999 - 2004
Spec D
Regular price
$274.00
$203.00
26% off
- Unit price
- /per
Prothane Front Sway Bar Bushings: Jeep Grand Cherokee 99-04 4.0L I6 w/ Red
Prothane
$55.95
- Unit price
- /per
Prothane Rear Sway Bar Bushings (REAR): Jeep Grand Cherokee 99-04 4.0L I6 w/ Red
Prothane
$45.95
- Unit price
- /per
Prothane Black 1in Lift Body Mount Kit: Jeep Wrangler 97-06 4.0L/2.5L
Prothane
$446.54
- Unit price
- /per
Mishimoto 10 Row Oil Cooler Thermostatic: UNIVERSAL Black
Mishimoto
Regular price
$472.00
$428.95
9% off
- Unit price
- /per
Mishimoto 19 Row Oil Cooler Thermostatic: UNIVERSAL Black
Mishimoto
Regular price
$594.00
$539.95
9% off
- Unit price
- /per
Mishimoto 10 Row Oil Cooler Non-Thermostatic: UNIVERSAL Silver
Mishimoto
Regular price
$407.00
$369.95
9% off
- Unit price
- /per
Mishimoto 19-Row Oil Cooler Non-Thermostatic (UNIVERSAL) - Silver
Mishimoto
Regular price
$531.00
$482.95
9% off
- Unit price
- /per
Mishimoto 10 Row Oil Cooler Thermostatic: UNIVERSAL Silver
Mishimoto
Regular price
$472.00
$428.95
9% off
- Unit price
- /per
Mishimoto 25-Row Oil Cooler Non-Thermostatic (UNIVERSAL) - Black
Mishimoto
Regular price
$504.00
$457.95
9% off
- Unit price
- /per
Mishimoto 25 Row Oil Cooler Non-Thermostatic: UNIVERSAL Silver
Mishimoto
Regular price
$504.00
$457.95
9% off
- Unit price
- /per
Mishimoto 25-Row Oil Cooler Thermostatic (UNIVERSAL) - Black
Mishimoto
Regular price
$555.00
$504.95
9% off
- Unit price
- /per
Mishimoto 19 Row Oil Cooler Thermostatic: UNIVERSAL Silver
Mishimoto
Regular price
$594.00
$539.95
9% off
- Unit price
- /per
Mishimoto 19-Row Oil Cooler Non-Thermostatic (UNIVERSAL) - Black
Mishimoto
Regular price
$531.00
$482.95
9% off
- Unit price
- /per
Mishimoto 25-Row Oil Cooler Thermostatic (UNIVERSAL) - Silver
Mishimoto
Regular price
$555.00
$504.95
9% off
- Unit price
- /per
Mishimoto 10 Row Oil Cooler Non-Thermostatic: UNIVERSAL Black
Mishimoto
Regular price
$407.00
$369.95
9% off
- Unit price
- /per
Mishimoto 25 Row Dual Pass Oil Cooler: UNIVERSAL
Mishimoto
Regular price
$409.00
$371.95
9% off
- Unit price
- /per
Mishimoto 19 Row Dual Pass Oil Cooler: UNIVERSAL
Mishimoto
Regular price
$351.00
$318.95
9% off
- Unit price
- /per
Edelbrock Head Gasket Set (4.0L I6): Jeep Grand Cherokee / Wrangler 91-06 4.0L I6 w/ Edelbrock Head
Edelbrock
$141.95
- Unit price
- /per
Bilstein B6 4600 Rear Shock Absorber (REAR): Jeep Wrangler TJ & Unlimited 1997-2006
Bilstein
Regular price
$154.85
$104.00
33% off
- Unit price
- /per
HPS Silicone Radiator & Heater Hoses Kit: Jeep Wrangler TJ 4.0L I6 2000 - 2001
HPS
Regular price from $241.00 Up to 13% off
- Unit price
- /per
3 colors
HPS Silicone Radiator Hoses Kit: Jeep Wrangler TJ 4.0L I6 2000 - 2006
HPS
Regular price from $155.00 Up to 13% off
- Unit price
- /per
3 colors
You’re viewing 1-40 of 1146 products
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.