aFe Twisted Steel Header — Jeep Wrangler / Cherokee / Grand Cherokee / Comanche 4.0L

Twisted Steel 409 stainless header for documented Jeep gas I6 4.0L applications

The aFe 48-46201 Twisted Steel header uses 1.5-inch 14-gauge mandrel-bent 409 stainless tubing, hand TIG welding, mitered merged collectors and a 0.5-inch head flange. The exact manufacturer separately lists Wrangler YJ/TJ, Cherokee XJ, Grand Cherokee and Comanche gas I6 4.0L applications. The complete selected Wrangler guide includes engine-hoist, motor-mount and intake-support work; its bolt-on description is not a simple two-fastener swap.

Key Features

• Selected aFe part 48-46201.
• 1.5-inch 14-gauge mandrel-bent 409 stainless primary tubes, hand TIG welding and mitered merged collectors.
• 0.5-inch thick one-piece head flange; premium port-matched gasket with aluminum fire rings described by the primary.
• One manifold gasket 05-01182, one exhaust flange gasket 05-01235 and two each supplied flange screws/nuts.
• Use an engine hoist before removing the left motor mount, and suspend the intake manifold using tie straps in the selected Wrangler procedure.
• Current exact manufacturer independently lists all five vehicle/model-year scopes below; no other engine or procedure is inferred from a shared engine name.
• Manufacturer references D-550-12 for some or all applications. Official indexed exhibit supports exact listed models/years, but full official order conditions remain unverified.

Fitment

Current exact manufacturer applications are Jeep Cherokee XJ 1991–1999, Comanche 1991–1992, Grand Cherokee 1993–1998, Wrangler YJ 1991–1995 and Wrangler TJ 1997–1999, all gas I6 4.0L. The complete exact-MPN named table supports 23 names and 27 disjoint scopes. Restore Cherokee SE 1994–1999, Grand Cherokee Orvis 1995 and Wrangler Sahara 1997–1999; preserve every documented gap rather than bridging intervening years. The selected full installation guide is for Wrangler YJ/TJ 1991–1999, not a complete Cherokee/Comanche/Grand Cherokee procedure. Manufacturer references D-550-12, whose official indexed exhibit names these exact part/model/year/engine scopes. Direct full-order access returned 403; confirm complete EO conditions and exact vehicle emissions eligibility before purchase or road use.

Specifications

What's Included

• The 48-46201 kit includes one selected 409 stainless header.
• One intake/exhaust manifold gasket 05-01182 and one exhaust flange gasket 05-01235.
• Two flange screws 05-40104 and two flange nuts 05-40103. Retain original shared cylinder-head bolts/washers and nuts/washers and original mount/accessory hardware as instructed.
• Engine hoist and tie straps are required tools, not supplied kit items. No catalytic converters, new oxygen sensors, downpipe, exhaust tips, intake filter or intake coupling are established as supplied.

About aFe Power

aFe Power develops application-specific intake, filtration, exhaust, cooling, tuning, suspension, drivetrain, and truck-performance components supported by product testing and documented installation requirements.

Related Parts

• Exact selected header and five current model/engine application scopes
• Complete selected 25-step Wrangler guide and formal parts list
• Complete exact-MPN named table with disjoint year scopes
• Official D-550-12 reference; full order access not verified
• Shop headers and manifolds
• Shop aFe Power

FAQ

It is a TIG-welded 409 stainless header for documented Jeep gas I6 4.0L applications, supplied with manifold/flange gaskets and two flange-fastener pairs.

No. Current exact manufacturer coverage separates YJ 1991–1995 from TJ 1997–1999. No 1996 vehicle mapping or earlier/later engine is inferred from the old broad YJ title.

No. The complete selected guide is headed Wrangler YJ/TJ 1991–1999 gas I6 4.0L. Cherokee, Grand Cherokee and Comanche fitment is separately explicit in current primary applications, but their model-specific installation procedures must be confirmed.

The selected guide removes the left motor mount and bracket and shared intake/exhaust fasteners. Suspend the engine before mount removal and support the intake with tie straps so neither is left unsupported.

The exact guide lists manifold gasket 05-01182, flange gasket 05-01235, two screws 05-40104 and two nuts 05-40103 with the header. Original shared cylinder-head bolts/washers and nuts/washers are reused.

No power-steering hydraulic disconnection is permitted by the selected guide: move the pump and bracket aside with lines connected. No fuel-line removal instruction is printed for this selection; do not borrow the four-cylinder header’s fuel procedure.

No. The manufacturer qualifies D-550-12 coverage as some or all applications. The official indexed exhibit names this part and the stated five model/year/engine scopes, but full official order conditions were inaccessible. Confirm exact emissions eligibility and complete conditions before road use.

The selected guide gives no numerical torque or mileage recheck interval. Tighten shared head hardware from the middle outward and recheck all work. The 7 hp/9 lb-ft figures remain primary claims with the exact chart and test conditions unlocated.

Installation Instructions

1. Confirm aFe 48-46201 against the exact vehicle and installed equipment. Inventory the actual components and follow the selected manufacturer instructions and current vehicle service requirements.
2. Confirm the exact listed Jeep gas I6 4.0L vehicle, installed configuration and emissions eligibility. Read the complete 25-step selected Wrangler guide and obtain exact vehicle service requirements; other listed models need their own model-specific procedure. Allow the vehicle to cool, use protective equipment, support it on specified jack-stand points and disconnect the negative battery terminal.
3. Loosen and retain the breather/intake hose clamps. Remove the breather hose, intake tube and serpentine belt. Move the power-steering pump and bracket aside WITHOUT disconnecting hydraulic lines.
4. From below, disconnect the oxygen-sensor wire connector and remove the two exhaust-pipe attachment nuts. Suspend the engine with an engine hoist BEFORE removing any left motor-mount hardware.
5. Remove the three mount-bracket-to-block bolts, bracket-to-mount nut/bolt and two mount-to-chassis nuts/bolts. Retain all hardware, remove the bracket and motor mount, and maintain engine support.
6. Suspend the intake manifold from the hoist using tie straps. Remove the nine shared bolts/washers and two nuts/washers. Ease the intake off its locating pins and suspend it slightly upward; remove the original exhaust manifold from beneath the vehicle and remove the old gasket.
7. Clean the head mounting surface without allowing debris into the ports. Place the supplied manifold gasket, selected header and intake on the head using the nine original bolts/washers and two nuts/washers, initially loose. Tighten from the middle outward using exact applicable vehicle requirements; this guide gives no numerical torque.
8. Reinstall the left motor mount and bracket using their retained original hardware. Install the supplied exhaust flange gasket on the new header, then connect the exhaust using the two supplied flange screws and nuts.
9. Restore the original oxygen-sensor wire connection to the correct harness plug and keep the wire clear of the header. Secure the power-steering pump and bracket, reinstall the stock intake tube and breather with retained clamps, and refit the serpentine belt.
10. Recheck all work, safely lower the vehicle and reconnect the negative battery terminal. The guide prints no fixed clearance or mileage recheck interval. No front/rear O2 bung-transfer, after-cat downpipe-removal or fuel-line procedure is borrowed from another header.

California Proposition 65 warning: this product can expose you to chemicals known to the State of California to cause cancer and reproductive harm.