XxRainyCloudsxX

Just Recently Bought a 2004 Civic LX,
Factory Engine,1.7-liter four-cylinder engine.
Figured i would start with buying a good intake and exhuast system first before i do any other mods to it.
My Qustion is Which intake and Exaust system would be the best for this type of Engine and would fit the best in the civic.
Ive looked around a little but im a little new to mod's So any help would be great.
Also if you could tell me a good place to buy from, or if it would be better to find a used one.

Pics.

gearbox

iTrader: (95)

prolly go with aem v2 intake, and any name brand exhaust (greddy, dc, apexi)

bman11

hey man, and 05 lx and i put a aem v2 in it, i love it sounds good. i have been looking for exhausts for a while now and having trouble finding some that will fit the lx that dont have to large of a price tag. personally i realy like the greddy se but around my place it retails at a grand, and shipping plus fees from anywhere else woujld b just as expensive. other option is to do an ex exhaust swap but to me anyways sounds like more than its worth, read triz faq about exhausts. just search his name

shasam1721

yea im trying to find how to get an adapter to make the greddy se catback exhaust fit the 04 lx sedan when they sell it for the coupe.

02civicsi02

Your better off just keeping the motor stock.

Kennykid2002

iTrader: (1)

Why revive threads?

sdaidoji

iTrader: (1)

if they are interesting or really funny, i would not mind, but this is a Intake/Exhaust Question (04 Civic LX) posted in the honda civic's members' rides forum.
run, noob! run!
try be be as succesful as Forest Gump and Run!

xRiCeBoYx

iTrader: (22)

I think that's the trend nowadays.. reviving 1+ year old threads.

02civicsi02

Wow I cant believe I didnt catch it that this is a yr old thread.

shasam1721

ive already got performance headers that i know fit my car cause i put them on for a week, but i want to be legal so im going to just get a hi flow cat make some 02 wire extensions and get a piece of pipe to make it all work from a muffler shop. im hell bent on this exhaust. ive heard some people are having trouble doing this setup. they get a CEL? and i figured they just attached 1 sensor to the headers and brought the other down behind the cat. o and does anyone know where you can get a carbon gasket for between the headers and the down pipe? (i cracked mine in half on accident...)

mac25

since i just posted this for someone else i'll past it here two for you. might answer some questions.



first off you need to know why you want an exaust set up.
power?
sound?
looks?

you won't make much power (hp or torque) even if you have a full setup, which i do.
i have
~k&n short ram intake, new $320 (but don't be stupid like me and buy brand nam, get it off ebay for $50 then buy a good aem filter)

~stock ex header (you don't need a bigger header if you have an ex since the exaust ports from the head match the header diameter. you only need bigger if you port your head)

~2in downpipe (not sure if it was stock buy it was on the exhaust when i bought her)

~2.25in megnaflow high flow cat. $100 new (make sure to get the one with the bunt whole for the air sencor between the two converter plates)

~2.25in megnaflow cat. back exhaust, $150 craigslist

~custom welded and cut for $170, for parts, labor, and tax.

with all of that i've seen minor gains in power and torque. my automatic is now at 8.2-8.5 seconds for 0-60, which is around the best time i've seen for a stock manual. so don't expect a rocket after you do intake and exhaust.

however it sounds amazing!!!!!!! and looks way better.

you also have to think about money. buying from ebay and craigs list is good for non vitale parts of your car.

now for your question. the lx (which my mom owns, has a very restrictive exhaust manifold, which has a built in catalitic converter. that will be your most restrictiv section of exaust flow. you have to remember that the smalest diameter size tube for your exhaust system (header,downpipe,cat. and cat. back) will be very restrictive even after you put a cat. back exhaust on, like you want. so if you want as much power as these bolt ons will let you have the ex header is definately better.

the ex header will bolt directly on to your lx head because both cars have the exact same engine. the lx has the d17a1 and the ex the d17a2 (there's also an a3 but don't worry). all the a2 means is that the ex has a vtec system attached to the same base engine that you have.

if you swap the header you'll need to buy a catolitic converter. what's nice is that a stock size cat., 1.25inch, is around the same price as a high performence high flow cat. (mine was $100 after tax). you'll also need to extend your o2 senosor.

there are 3 o2 sensors. one in your intake, one after the header and one in the cat.

the one in the cat. is the one you'll need to extend (just cut the wires extend with wire with high heat rated insolalation wire and remember to get the type of cat. with the air sensor whole in between the two converter plates like i mentioned above).

if you're just going for the exhaust but don't want it to do anything but look cool and sound a bit loader then just take what you bought to a GOOD exaust shop tell them to weld a pipe to extend it to the cat in your lx. they might need to add some 3bolt flanges but any decent shop can do it.

if you are going for the maximum amount of gains you can get off intake and exaust you also have to think about the diameter of piping you use. you need back pressure (i don't know the exact sciennce of it so google it). if you already baught a 2.5inch cat. back don't despare but try to get a 2.25in downpipe and cat. 2.25 is better for our car's since the engines are so low in displacment.

but if you're eventually going FI (forced induction, ie turbo or supercharged), then you'll want 3inch piping so your car can breath properly with the much higher volume exhaust of the FI setup.

2.5 is ok and alot of people us it even on the 7th gen civics, but i've read on this forum and others that 2.25 is best for NA (naturally asparated engines, so stock engines without turbo or supercharged).

sdaidoji

iTrader: (1)

OK, if Gearbox is seeing this, please stick Mac's post - not the thread, but his post!

mac25

thx sdaidaji! lots of people on here have helped me out and i want to do the same for others.