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How to Install AFE Direct Fit Catalytic Converter - Rear (04-06 4.0L Wrangler TJ) on your Jeep Wrangler

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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.

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

Step 2: Remove the O2 sensors between the FRONT & REAR of the OE cats.

Step 3: Remove the transmission cross member. USING A FLOOR JACK SECURE THE TRANMISSION and remove the nuts securing the cross member to the transmission.

Step 4: Remove the bolts on the cross member to the chassis and remove the cross member.

Step 5: Remove the (x2) nuts securing the catalytic converters to the stock exhaust system.

Step 6: Remove the (x4) 15mm bolts securing the catalytic converters to the stock exhaust manifold.

Step 7: Remove down pipe. Be careful when initiating this step removing the four bolts will cause the catalytic converters to fall so it is a good idea to have the help of a second hand when removing this down pipe.

Step 8: From the flange measure CUT 23.500” (See figure #2).

Step 9: Re-Install the OE Catalytic coveters to the OE exhaust manifold secure with the (x4) bolts.

Step 10: Install aFe Rear cat Replacement to the OE exhaust system using OE nuts and (1x) 2.5” band clamp. DO NOT TIGHTEN.

Step 11: Tighten the (x4) 15mm bolts from step 9. Tighten the (x2) nuts from step 10. Tighten the band clamps

Step 12: Re-Install the cross member to transmission and the chassis
using the original nuts and bolts and tighten.

Step 13: Re-Install O2 sensors between the FRONT & REAR of the cats.

Step 14: Re-Check all your work.

Step 15: Remove vehicle off jack stands.

Step 16: Re-check all bolts/nuts clamp after 50-100 miles.