Gibson Cat-Back Exhaust System

WHY?  Because I just can't leave well enough alone, that's why.  The new Frontier runs great, gets amazing fuel economy, and has a decent exhaust note for a stock system (to get a look at the stock exhaust, see here).  Since an aftermarket exhaust system is one of the first mods done by many owners, I just had to know if it would add any real horsepower or economy to an already fine vehicle.  I'd like a more aggressive exhaust note, but I don't want the annoying drone in the cabin that seems to accompany most aftermarket exhausts.  I decided on the Gibson system (Swept-Side Exhaust, #12211) since it has a reputation of utilizing one of the more conservative mufflers available.  I chose the aluminized steel model over the stainless unit because I seldom keep a vehicle long enough for the muffler to rot and I didn't want to pay the premium for the stainless system; if you are one of those owners that keeps a truck for 10 years the stainless model might be a good investment.  Most vendors offer similar pricing, so I settled on AJ-USA because they offered free shipping on the system and I have had good experience with them in the past.  Their web site was clean and easy to navigate, and I placed the order online.  $393.97, shipping included.

SERVICE.  Pretty darned good.  I received an email confirmation after placing the order, and I was able track my order status on their site.  Four working days after placing the order I began to wonder why I hadn't received a shipping notice--I heard a knock on my door, and it was the FedEx driver with the shipment!  The system arrived in the original packaging from Gibson's warehouse, and when I opened the box everything appeared to be in good shape.  All parts and instructions were included.  There were no obvious dents or dings, and all of the welds looked to be clean.

INSTALLATION.  This job could be accomplished by an owner with modest mechanical skills and required only basic hand tools, though a set of jack stands is recommended.  Working carefully, I had the entire system installed in under about 1-1/2 hours, including photography.  The installation instructions were illustrated and adequate for the job, but here is how I got it done:

1.  It's much easier to work if you can get the truck in the air, so I used my floor jack and raised the Frontier and supported it on jack stands:

2.  Lay all the pieces on of the new system on the floor to see that everything on the parts list is present and undamaged:

3.  Disconnect the small ground strap attached to the vibration damper on the stock tailpipe; do this now because it is easily overlooked later:

4.  Remove the 4 nuts (2 on each side) from the exhaust flanges attached to the exhaust resonators.  Save the nuts and gaskets for use with the new system:

5.  Loosen the clamp on the stock tailpipe just behind the muffler:

6.  The instructions tell you to lubricate the rubber grommets in the exhaust hangers and slip out the hanger bars, but that is really difficult; I have found that it is much easier to drop the brackets by removing the two bolts that hold them into place:

7.  Drop the two front hanger brackets and slide the stock exhaust system forward; it will slip out of the rear hanger bracket and the entire assembly will come crashing down on your chest, knocking the wind out of you and making you awfully glad that you waited for the exhaust to cool before starting the project.  Pull the tailpipe loose from the muffler and the stock system is now history.

8.  Attach the new Y-pipe to the exhaust flanges on the catalytic converters; use the stock gaskets and nuts and don't forget to re-attach the ground strap to one of the bolts on flange on the driver's side.  Don't tighten the nuts yet.  Slip the hanger arm into the hanger grommet:

9.  Slide a clamp over the end of the Y-pipe and slip the resonator onto the end of the Y-pipe.  Secure the two with a clamp, but don't tighten yet:

10.  Slide the circular band clamp and hanger around the muffler and slip the inlet end of the muffler onto the end of the resonator; the muffler outlet should be at the twelve o'clock position:

11.  Slide a circular clamp over the new tailpipe, slip the pipe over the rear axle and fit the end over the muffler outlet.  Slip the tailpipe hanger into the rubber grommet and use the clamp to attach the tailpipe to the muffler:

12.  Check to see that all parts are fit together snugly and check the entire length of the system to be sure that everything is aligned properly and will not contact or rattle against any other parts.  Starting from the front, tighten all flanges, clamps and brackets.  Position the stainless tip and tighten the clamp to hold it in place.  Start the engine and listen for leaks.  Done!

RESULTS.  I'm really impressed with the fit and finish of this system; I've installed many exhausts over the years, and some of them required grinding, hammering, and/or bending to make them fit.  The Gibson unit fit into place perfectly.  The sound is nice, with an aggressive snarl on acceleration but without the annoying drone at highway speeds.  Want to hear how the new system sounds?  Click here for a clip of the stock exhaust, then click here to hear the Gibson.  For a look at the dyno charts, click here; the new system added about 5.7 horsepower and 5.7 ft/lbs torque at the rear wheels, distributed pretty evenly across the power band.  On my regular test loop, my gas mileage has increased 1.1 mpg--almost 5%.

WORTH THE MONEY? It's a mixed bag; if you have the cash to spend and like the sound, go for it.  You'll get slightly more power and slightly better gas mileage.  If you're on a budget and want the sound you'd probably be better suited going to an aftermarket muffler or having a private shop fabricate a muffler/tailpipe combo.  You'll probably not get much of a power increase, but the average Joe can't feel 5 hp in the seat o' the pants dyno anyway.