Want a job that'll only take you about an hour?
Looking for a task that will give your Jeep about a 1.5% improvement in gas mileage and add 4.5-hp @ 4,400 rpm? Then you'll want to order a new Gibson muffler (part # 17303). You also add 4.5 ft-lbs of torque @ 4,400 rpm, and you'll only need a minimum number of hand tools. In fact, all you'll need is a can of WD-40, a small set of socket wrenches and a large pry-bar or screwdriver. Although we used a hydraulic lift to ease picture taking, providing more clearance to R&R the muffler at home, could be accomplished with a set of drive-up ramps or a floor jack and a pair of jackstands, but neither is really required. As I said earlier, this task will only take you about an hour and it's as easy as changing just one shock absorber. It's a quick and easy upgrade that'll give you a satisfying sound at all engine speeds. By the way, if you're a rock crawler or into heavy-duty trails, you might want to order an extra set of stainless steel tips just in case you tweak them while sliding down a rock.
1) Unbolt the band clamp securing the muffler to the pipe from the catalytic converter.
2) Use WD-40 liberally on the two OEM rubber hangers located on each side of the muffler, and pry the welded hangers from the grommets. Do not damage or remove the rubber grommets, you'll need them to support the Gibson muffler.
3) Remove the OEM muffler and set it aside.
4) Slide the hangers onto the Gibson muffler and into their respective grommets. (You may need additional WD-40 at this time.)
5) einstall the OEM band clamp and tighten it.
6) Slip on the stainless steel tailpipe tips and tighten their bolts. After about 25-50 miles of operation, go over all three bolts once again and make sure they are tight.
7) We ran the Rubicon on the dynamometer before and after the installation to ascertain the base horsepower and torque and the new ratings.
