SJJ25R / SJJ25S
2018 Jeep Wrangler JL 2DR & 4DR 3.6 V6 HGC
Stainless Steel Catback System
After you have inventoried the parts begin by placing your Jeep on a lift or 4 jack stands so you can work safely
under your vehicle.
Unbolt the factory muffler using the 15mm socket and remove the muffler from the vehicle. To aid in the removal
presoak the bolt and nut as well as the rubber bushings.
Next using a 13mm socket loosen the ball socket clamp at the end of the factory down pipe and remove the fac-
tory mid-pipe. Save all the rubber hanger bushing they will be reused. (Removal of the skid plate is recommend-
ed for this step.)
Now it’s time to start the installation of your new cat back. Begin by installing the tailpipe into the two factory
rubber hangers located above the sway bar followed by the muffler using two HVC21 band clamps.
Next install the new MJJ23 mid-pipe using the HVC21U ball socket clamp. On 4 door models no modification is
needed to the mid-pipe. For 2 door models you will need to cut the mid-pipe to length. Do this by seating the ball
socket portion into the factory down pipe then hold it against the nipple of the muffler. Mark the mid-pipe allowing
enough engagement into the muffler. A general rule is plus 1 ¾” from the end of the muffler nipple.
Now that you have the major components loosely installed align the system (the bends in the mid-pipe will run Now that you have the major components loosely installed align the system (the bends in the mid-pipe will run
parallel to the ground) and tighten all clamps. Make sure the ball socket is seated and the U- clamp captures
both parts equally. This is critical to creating a good seal. Air tools are highly recommended for this part.
Now start your vehicle and check for leaks. It’s not uncommon to see condensation coming from the relief cuts in
the pipe for the first few hundred miles. Double check all clamps and hardware for tightness after the first week
of operation and adjust accordingly.
SJJ25S
SJJ25R
1 TJJ25 Tailpipe
1 MVR200S or MVS11 Muffler
1 MJJ23 Midpipe
2 HVC21 Clamp
2 HVC21U Clamp
Pypes Performance Exhaust
2705 Clemens Rd B103 Hatfield, PA 19440
www.pypesexhaust.com 800-421-3890