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SLP Catted X-pipe Installation Guide (99-04)

AmericanMuscle Installation Garage

The below installation instructions work for the following product:
  • 1999-2004 Ford Mustang Catted SLP X-Pipe
  • AmericanMuscle Installation Garage
    Here at American Muscle, we're all about DIY (do it yourself). Of course, there's nothing wrong with seeking out a little bit of tech help prior to taking on an installation on your own. Our Mustang installation guides will provide valuable instructions and hopefully answer any how-to questions that you may have along the way.







    The following instructions are for the installation of the 1999-2004 Mustang V8 SLP Catted X-Pipe.

    Required Tools:

    • 8mm wrench or ratchet
    • long screwdrivers (x2)
    • 3/8's drive ratchet with long extension and swivel head attachment with 15 mm and 13 mm deep sockets
    • Small adjustable light
    • PB blaster (optional)

    image 01

    Installation:

    1. Disconnect the cars battery

    2. Securely raise the car with enough room to work safely under the car.

    3. image 02

    4. Remove the nuts from the exhaust manifold using a 15mm socket with long extension on the driver side. While on the passenger side you will need to use the swivel attachment. It is recommended to use "PB Blaster" (or other similar product ) to loosen the nuts.

    5. image 03

      Above image of the cars driver side


      image 04

      Above image of the cars passenger side showing swivel attachment in use.


    6. Now that you have the front bolts loose turn your attention to the back of the car and remove the mid pipe from the cat-back a 15 mm socket will work here as well.

    7. At this point your mid pipe should want to drop down on it's own, the only thing that will be holding it in place is your O2 sensors. Carefully remove the O2 sensors using a long screwdriver or your hand if possible.

    8. image 06

    9. Now that the mid pipe is off the car you will now need to swap out the 02 sensors and install them into the new X-pipe. Be sure to keep the O2 sensors in the same locations that you removed them from the old mid pipe.

    10. image 07

    11. Now is the time to start installing the new X-pipe. You will want to replace the old exhaust gasket with the new one from the kit. In the below images you can see the old gasket verses the new gasket.

    12. image 08

      image 09

    13. With the new gasket in place you can loosely install the passenger side down pipe, do not tighten. You can also reattach the front O2 sensor at this point, green to green.

    14. The driver side down pipe requires the removal of the old studs, so that they can be replaced the with regular bolts. Now loosely install the drivers side down pipe, do not tighten. You can also reattach the front O2 sensor at this point, green to green.

    15. image 10

    16. The next step will be to install the catalytic converters onto the down pipes. Be sure to slide the band clamps on to the piping before installing catalytic converters. Slide the catalytic converters into place with the heat shield facing up. Only snug the cats into place, do not tighten yet. Repeat for other side.

    17. image 11

    18. Once the cats are in place you can install the new X-pipe. I found it easier to insert the new X-pipe into the existing cat-back first. Then insert the X-pipe into the catalytic converters. Remember to keep everything loose for now, do not tighten. It should look like the image below.

    19. image 12

    20. Now reattach the rear O2 sensors, blue to blue. Note: On the 2004 models you will need to use O2 extensions, you will want to run the extensions over the transmission cross member to keep them away from the heat of the exhaust.

    21. image 13

      The above image pertains to the 2004 mustang's only

    22. Now with everything in place check the entire exhaust system for clearance against the body and moving parts. Reposition the exhaust where needed so that everything fits correctly.

    23. Now you can start tightening the bolts. Starting at the exhaust manifold tighten the bolts from front to back. The exhaust manifold's should be tightened to 30 ft/lbs and flange bolts should be tightened 26 ft/lbs.

    24. Reconnect the battery. Start the vehicle, inspect for any exhaust leaks. Double check all fasteners adjust as necessary.

    25. Now go to and enjoy the new sound and power your New SLP Catted X-pipe has to offer.

    Installation instructions provided by AmericanMuscle customer by Chris Morris



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