Free Shipping On Orders Over $49. Details

Talk to a Mustang Enthusiast
M-F 8:30A-11P, Sat-Sun 8:30A-9P
Win $15,000!! Enter Now

Best Sellers

Magnaflow Catback Exhaust ('99-'04 GT / Mach 1 / Bullitt) - Installation Instructions

Installation Time

2 hours

American Muscle
Shop Parts in this Guide


Warning: when working on, under, or around any vehicle exercise caution. Please allow the vehicles exhaust system is cool before removal, as exhaust system temperatures may cause severe burns. If working without a lift, always consult vehicle manual for correct lifting specifications. Always wear safety glasses and ensure a safe work area. Serious injury or death could occcur if safety measures are not followed.

Step 1: (Carefully read all instructions before installations)

Disconnect the vehicles battery before removal of the OEM exhaust. This will allow the computer to reset itself with the new system, and prevent electrical accidents. To remove the OEM exhaust system, unbolt the clamps fastening the muffler inlets to the over axle pipes. Unbolt the muffler hanger brackets from the frame, and remove the mufflers from the vehicle (the brackets will be reused) Remove the over axle pipes in a similar fashion. Do not discard the OEM band clamps or damage the OEM rubber insulators, as they will be reused to mount the new system.

Step 2:

Remove the OEM hanger brackets from the mufflers and reattach them to the frame of the vehicle. (Make note of the hanger isolator orientation as improper installation will cause fitment issues). Leave all clamps and fasteners loose for final adjustment of the complete system. Install the new mufflers by fitting the welded hangers into the rubber insulators in the brackets. Fit the new over axle pipes into place and fasten them to the catalytic converters and new mufflers using the OEM clamps at the converters and the supplied 3" clamps at the mufflers.

Step 3:

With all components mounted loosely, adjust the system for overall aesthetics and clearance of frame and bodywork. (MAGNAFLOW recommends at least 1/2" of clearance between the exhaust system and any body panels to prevent heat related body damage or fire.)

Step 4:

Once a final position has been chosen for the new system, evenly tighten all fasteners from front to rear. the supplied hand clamps must be very tight to properly align the pipes and prevent leaks (Approximately 65ft-lbs). U-bolt clamps should be tightened to approx. 30-35ft-lbs. Inspect all fasteners after 25-50 miles of operation and retighten if necessary.

Best Sellers