Truck owners love how powerful their vehicles are. Trucks need lots of power because they're designed to haul and tow heavy loads without difficulty. However, many truck manufacturers use fairly quiet exhaust systems on their vehicles, despite their powerful engines. If you want your truck to sound as powerful as you know it is, or if you're aiming to reduce the constrictions on the exhaust, then consider adding to or altering your truck's exhaust system.
Luckily for you, the factory exhaust system on your truck is efficient, and can be easily improved with just a few modifications. The exhaust manifold is the first component of the exhaust system. It directs exhaust from each cylinder together into one or two main exhaust pipes. These are usually fairly efficient and don't need to be replaced. If you decide to change them though, find a good set of headers with ceramic coating and factory mounting points for sensors. Usually though, the factory exhaust manifold will be perfectly fine for your needs.
The next components which the exhaust gases travel through are the catalytic converters. There's really no benefit to changing or modifying these, and taking them off is a bad idea. Today's modern catalytic converter is very efficient and legally required, so it makes sense to leave it alone. You would only consider replacing the factory catalytic if you were adding an extremely powerful engine upgrade, like a turbocharger or supercharger.
As they leave the catalytic converters, exhaust gases will cool down a bit and enter the muffler. The factory mufflers usually aren't too restrictive, and replacing them won't make a huge difference in the amount of hp or torque you get. The average change is about 3-5 hp and 5-10 ft-lbs of torque. After market mufflers, however, will make a dramatic change and are definitely worth the money. Your truck will sound much better! After the mufflers, exhaust exits the truck via the tailpipe. You can add tailpipe tips to this part, but it'll be purely for decoration purposes, and won't affect the exhaust system in any way.
Since changing the factory muffler will have the biggest effect on your exhaust system, they're the most logical component to replace. When you're looking at after market mufflers, here are some things to consider:
First, ask yourself if you really want to be hearing the exhaust ALL the time. If you do, make sure to take that into account when selecting your muffler. If you'd prefer not to hear the muffler in the background as you're driving down the highway, choose a muffler that's not described as loud. You can look online or at your local muffler shop for more help on finding the perfect muffler. There are even sound clips on many muffler manufacturers' websites now so you can hear what your muffler will sound like before you buy.
Second, do you want something that people can slightly hear when you drive by, or do you want something so loud that the neighbors know exactly what time you leave for work every morning? Words like "racing" or "glasspack" usually indicate exceptionally loud mufflers, so watch out for those terms unless you want a lot of attention.
Choosing between a single or dual exhaust muffler is another important decision you'll have to make. If your truck came with a single exhaust, then a single after market exhaust will be enough to keep good performance. If you prefer to get a dual exhaust, be prepared to spend more money in exchange for better sound and look. Make sure your installer works around your trailer hitch, or leaves room for one, just in case you decide to add one later.
Your final decision is which exhaust material system you'll use. The right material for you will depend on where you're located geographically. If it's anywhere near a saltwater body, buy stainless steel. It may cost more, but stainless steel will be a wise investment since the saltwater in your environment is harsh on regular galvanized or aluminized steel. Drivers in dry climates won't really benefit from the extra cost of stainless steel, since it'll take years for rust damage to occur if it gets into the system.