1979-83 Fox Body Mustang Midpipe Installation Instructions

If you are looking for an aggressive sound paired with more HP & TQ, look no further than an off road or catted mid pipe for your Fox Body Mustang. This quick and easy installation guide will show you how to get more horse power & torque out of your 79-93 302 Mustang!

Tools Needed:

  • Hacksaw or Sawsall
  • Common House Hold Tools
  • Welder(See Disclaimer)

Installation Instructions:

Step 1:
Begin by disconnecting your negative cable from your battery, as you will be disconnecting some electrical components. Place the vehicle on a lift or (4) jack stands at maximum height. This will aid in an easier installation. Note: Make sure to support your catback just past the connection point between the factory h-pipe.
Step 2:
Unbolt the factory h-pipe from your cat-back. Soaking your factory mounting points with penetrating oil will allow for easier removal. Next, disconnect your 02 sensors from the factory wiring harness and remove them from the h-pipe using a 22mm wrench. Remove the bolts at the manifold/header end. Be careful, as old or rusty parts tend to break easily.
Step 3:
Begin by installing the driver and passenger side down-pipes/front legs, snug the bolts but do not tighten.
Step 4:
Next, install the x-pipe or h-pipe portion. Position the ball portion so that the long leg is on the driver side and the short leg is on the passenger side. Slide the (2) band clamps (if equipped) on to the front legs of the x-pipe/h-pipe.
Step 5:
Now, slide the x/h-pipe on to the driver and passenger down-pipes matching the ball ends to the cat-back. Re-install the factory cat-back hardware and snug tight.
Step 6:
Supporting or jacking up on the center of the x/h-pipe will aid in the system having the most possible ground clearance. Finish by tightening all the hardware.
Step 7:
After all the connections are tight, start the engine. Check and listen for any leaks. Make sure to check your connections periodically as they may come loose.

For a cleaner appearance and more secure installation, we highly recommend welding all slip fit connections. If you live in a geographical area that has harsh winters or sees a great deal of precipitation, the use of high temperature paint over the welded areas can help to prevent surface rust and premature corrosion.


Not all exhaust systems will require welding. However, we recommend reading over the supplied instructions in your mid pipe exhaust kit purchased from LMR. This will ensure proper installation of your Fox Body Mustang x pipe or h pipe exhaust.