First Off, lets talk about the advantages of an aftermarket exhaust system. As many of you may know, the main purpose of the exhaust components is to minimize pollution; both sound and air. In addition, exhaust tubing creates an effect known as back pressure, which to make a long story short, allows for you Naturally Aspirated engine to produce some extra torque, while sacraficing a small amount of horsepower. There are 3 main "goals" of an aftermarket exhaust system:
1. Create the shortest, straightest path for the exhaust gas to travel. In otherwords, create a less-restrictive path. This helps to add a bit of top end power
2. While creating a less restrictive path, exhausts must also retain a decent amount of backpressure in order to allow the engine to make enough low end torque.
3. The most ovbious reason, to make the car sound "cooler"

DISCLAIMER: in some states (california is the worst) there are very strict emissions laws. Modifying your exhaust systems can cause your car to fail if u dont know the tricks of the trade (see rotarybzzz's How To Pass Emisions Thread). In addition, many states have sound ordinances regarding exhaust/total car volume. In many cases, the limit is 95dB. Most exhaust systems will comply with these laws, but some do not. Make sure you do your research before you spend your hard earned money!

There are 4 MAIN parts when it comes to exhaust systems: Headers, Cat-Converter, Piping, Muffler. I will give info on a few of the more popular brands

Headers:Aftermarket headers allow for the gases to flow better. They often have larger "collectors." They are either 1 or 2 pieces (self explanitory), and are either 4-1, or 4-2-1 (way the piping runs, ex. 4-2-1= 4 right off the ports, which flow into 2 pipes, which flow into a single downpipe). Headers bolt up to the Catalytic Converter. There are a few good choices when it comes to choosing a header:

1. Greddy (TRUST in Japan) S.S. 4-2-1 header for 5th gen accords. 2 pieces, and stainless steel to resisit corrosion. High Quality and 50 st. legal $380ish
2. DC Sports Ceramic for 4th gen +. 4-2-1 design, 2 pieces. cheaper than stainless steele. coated with ceramic to absorb heat and keep the engine bay cooler $300ish
3. DC Sports Stainless Steel for 5th gens. basically same design as the greddy, made in the USA $380ish
4. Comptech Header for 6th gen v6's. i know very little about this specific product, except that it can free up quiet a bit of power. Comptech is definantly a high end manufacturer $1000+
5. Custom: For most people, a complete custom header is out of the question, but custom downpipes are available, though without the use of an aftermarket header, they serve little purpose
6. Ebay - like the saying goes, you get what u pay for. Header design is very complex, and most "real" headers a designed with the molecular level in mind...

Catalytic Converters: The role of the catalytic converter is to oxidize the dangerous carbonmonoxide into its less dangerous cousin, carbon dioxide, as well as burn off excess gas that was never burnt during combustion. Modification of the cat (as it is called) is not recomended on 96+ accords, as there is an 02 sensor located in the cat on these models (this is where the term OBD2 comes in, see bottom for explination), and a non-properly working cat will result in CEL/Horriblegas mileage. There are basically 3 types of cat modification:

1. High-Flow cats: there are numerous brands (Carsound, Random Technology, etc.) these allow for a fully functional catalytic converter that at the same time, is less restrictive than the stock model. Many of these care Legal in states w/ emissions test, but make sure you verify if that situation applies to you. $175ish+
2. Test Pipe: Test pipes are basically a straight tube that takes place of the cat converter. In most cases, they are illegal. Test pipes are the least restrictive off all when it comes to cat's, yet they MAY cause a loss of low end torque. Some muffler shops will make one for you (they legally cant do the instal though), and some are available on EBAY $40ish
3. Gutted Cat aka. Flamer Thrower: The ghetto way of doing things. basically, it involves taking a screw driver and scraping out all the linings of the cat, which oxodize the incoming gases (these are carcenogenic BTW). Once again this will create less restriction in some scenarios, but can cost you low end torque. They do however give you the ability to shoot massives flames out ur muffler at times. $Free + you and your friends all get cancer


Cat-Back Exhaust Systems: As the name suggests, cat-back exhaust bolt up to the cat, and then run all the way to the muffler (which comes w/ the package). For NA engines, piping diameter should run around 60-80mm or 2-2.5in. Remember, the larger the piping, the less the backpressure = decreased low end torque. When paired w/ a good header and intake, you should begin to see SMALL gains in power at the higher end of the powerband. The system should come with new gaskets to go between the flanges that connect the numerous pipes, and in some cases, a removable silencer which is placed in the end of the muffler to help decrease the sound (though this eliminates any power gained by the catback). In addition, it should utilize factory hangers. For those of you who live in the snowbelt, it is important that you choose an exhaust with Stainless Steel piping, as it will resist corrosion. There are literaly dozens of excellent cat-back systems available, but i will go through the most common for accords.

1.Apex'i: World Sport & World Sport 2: Available for 4th-6th gen accords. Origonal: Mild Steel Tubing, Stainless Steel Muffler; W.S 2: All Stainless Steel. Often choosen by those who want a "sleeper"car. Very quiet untill WOT, when it gives out a distinctive low growl. "OEM Style" muffler w/ large outlit tip. $400ish
2.Greddy: Evo & Evo 2: 5th-6th gen accords. Origional: Mild Steel Tubing, Stainless Steel Muffter; Evo2: All Stainless Steel. Straight through design (muffler does not look like a maze when cross sectioned, but rather a straigh through path). The Evo is designed to sit higher up from the ground, improving ground clearance for lowered cars. Somewhat loud, with a full, deep tone.
3. Greddy Sp & Sp2: 4th-6th Gen. Same scenario as the Evo vs. Evo 2. Straight through design. One of the most popular exhausts regardless of make/model. Basiacaly, a more expensive, louder version of the Apex'i W.S. $500-550ish
4. Tanabe Super Hyper Medallion: 4th-7th Gen. Mild Steel piping and Stainless Muffler and tip. Straight through design, similar styling to the WS and SP. $500ish for single outlet, $700ish+ for V6 dual outlet
5. Tanabe Super Racing Medallion: 5th Gen. Same as above, yet mirrors the Japanese N1 style muffler. Apparently this specific setup is VERY loud. $550ish
6. DC Sports: 4th-6th gen. DC is one of the most well known domestic tuner companies, though they were recently bought out by AEM, causing their prices to drop significantly which means more savings for all of us. Utelizes a "pre-muffler" silencer to drown out the high pitched frequencys that are soo common of 4cyl cars. "OEM Style" muffler with huge 4" outlet tip
7. Thermal R&D CL Style: 4th-6th gen. Arguably one of the best exhausts for the Accord. Mild/Stainless Steel. Specifically designed for cars that are more higly tuned / are driven more aggressivly. Very deep, throaty sound. Look very much like OEM muffler, (EX style with dual tip).
8. Custom: Wether you order the piping from a place like Kteller.com (a member here), or have custom work done at a shop, be sure to use mandrel bent stainless steel piping, and that u match it with resonators/mufflers that will give you just the tone quality you desire. The advantage is that these are usually less expensive if done right. The downside is you dont neccesarily get a proven design, and you loose the "bling-bling" name brand factor.
9.Ebay: Personally ive had mixed experiences with Ebay exhausts. My best friend has a 3" DP back SS exhaust from ebay on his 89 Rx7....it didnt come with resonators so its incredibly loud, but when analyzing the welds, they looked of suprisingly high quality. Basically, if u choose an off-brand on ebay, you run a big risk, but sometimes the results can be just as good


Mufflers & Universal Aftermarket Mufflers: As the name suggests, once again, the muffler's main goal is to minimize the sound. OEM Mufflers are usually like a hollow box, with a maze-like path running through it. This, with help from sound dampening material with the muffler, help to absorb sound. Some people choose to bypass the whole cat-back system, and simply attack a universal muffler. In this scenario, they are basically only achiveing #3 on the list of reasons for an after market exhaust (see above). Many companies who make entire catback systems also offer universal mufflers. The actual goal of these aftermarket mufflers is to be used in a cutom setup (see #9 of "Cat-Back Exhaust"). This allows for some creativity in exhaust setup.
1. Apex'i N1 Universal Muffler. Avaiable in a wide variety of colors. By using these mufflers w/ a custom system, Accord owners can have an exact replica of the famous Apex'i N1 Slant Tip Cat-Back (very very sexy looking IMO) $200ish
2. Magnaflow. Magnaflow makes a wide variety of muffler designs, from OEM style to N1 style, theyve got almost everything. These mufflers usually are somewhat quiet, but at WOT the can roar with a nice deep tone. $70-100+
3. Ebay. Ebay offers a number of imitation mufflers. I would avoid them at all costs, as they use very poor sound insulators which will easily burn away through daily driving, making ur car sound like a constant nuclear explosion, and no one wants that. $.01-$50+

Heres a few key things to know when it comes to accord Exhaust:
-Exhaust Ports for F22/F23 (stock accord engine) o oo o
-Exhaust Ports For H22 (most commonly swapped engine) o o o o
In other words, F22/23 headers do NO work on H series engines

-Pre '96 Accords are OBD1, meaning that there is one O2 sensor, located before the catalytic converter.
-'96-on Accords are OBD2, meaning theres an 02 sensor located within the cat.

-As previously stated, for NA engines, back pressure is neccesary. However, for custom-made turbo exhaust systems, back pressure is your worst enemy, as it limits the turbo's ability to maximize power. Therefore, if and only if you are planning on turboing, choose a 2.5-3" diameter piping.