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How to Install AFE Twisted Steel Shorty Headers (91-99 4.0L Wrangler YJ & TJ) on your Jeep Wrangler

Tools Required
  • Flat Head Screwdriver
  • ½" & 9/16" Wrench
  • 15mm & 18mm Wrench
  • 12mm, 15mm & 18mm Socket
  • 3/8” Ratchet
  • 3/8” Swivel Socket Adapter
  • Engine Hoist
  • Tie Straps
Extreme Terrain
Shop Parts in this Guide

Parts Included:
• Header (48-46201)
• Gasket (05-01182)
• Flange Gasket (05-01235)
• Screw (05-40104)
• Nut (05-40103)

CAUTION: Allow time for your vehicle to cool down prior to installation. When working on or under your vehicle proceed with caution. Exhaust systems reach high temperatures and may cause serious burns. Wear protective safety equipment; eye goggles and gloves to ensure a safe installation. aFe recommends professional installation on our products.

1. Support the vehicle on jack stands and disconnect the negative battery terminal from battery.

2. Loosen hose clamps securing breather hose and intake air tube. Remove breather hose and intake air tube.

3. Remove the serpentine belt.

4. Remove the power steering pump and bracket to move the pump out of the way. DO NOT disconnect the lines.

5. From under the vehicle, disconnect the oxygen sensor from the wire harness.

6. Remove the two nuts securing the exhaust pipe to the stock exhaust manifold.

7. Using an engine hoist, suspend the engine from the engine bay to prevent from dropping down as the left side motor mount will be removed.

8. Remove the three bolts securing the left side motor mount bracket to the engine block.

9. Remove the nut and bolt securing the left side motor mount bracket to the motor mount. Remove motor mount bracket.

10. Remove the two nuts and bolts securing the left side motor mount to the chassis. Remove motor mount.

11. Suspend the intake manifold to the engine hoist with tie straps. The intake manifold shares the same bolts and washers with the exhaust manifold.

12. Remove the nine bolts/ washers and two nuts/ washers securing the stock exhaust and intake manifold to the engine.

13. Remove the intake manifold off the pins by wiggling out and away from the engine. Suspend slightly up and then remove the stock exhaust manifold from under the vehicle.

14. Remove the intake/ exhaust manifold gasket.

15. Ensuring that the cylinder head is free from any dirt and/or debris, install the supplied gasket, aFe Twisted Steel Header and intake manifold onto the cylinder head using the nine original bolts/ washers and two nuts/ washer but do not tighten.

16. Tighten the nine bolts/ washers and two nuts/ washers from step 15 starting with the middle and working your way out.

17. Install the motor mount and the motor mount bracket using the original hardware from steps 8-10.

18. Install the supplied exhaust flange gasket onto the aFe Twisted Steel Header.

19. Install the exhaust system using the two supplied flange nuts and screws then tighten.

20. Plug the oxygen sensor wire back to the correct wire harness plug and ensure that the wire is away from the header.

21. Secure the power steering pump and bracket then tighten.

22. Install the stock air intake tube and breather hose using the original hose clamps and tighten.

23. Install the serpentine belt..


25. Remove vehicle off the jack stands and re-connect negative battery terminal.