EliteCM.net

Stock Exhaust Manifold Removal


1.Pull your TSX into your work location. This is preferably a clean and flat concrete surface.
2. Pop and prop the hood. If the engine is hot, allow the motor to cool. You can speed up this process by aiming a good sized fan at the motor. (I just rest my plastic-bodied fan directly on top of the motor and fire it directly down)
3. Remove the factory heat shield from the exhaust manifold. There are 3 bolts (12mm) securing it to the upper portion of the manifold. the lowermost bolt is a bit of a stretch to reach - you may have more success getting at it from below. Fortunately I was able to reach it with my air-powered socket wrench (air tools sure are handy sometimes).
4. With a 14mm socket and a breaker bar (use a short extension if you have clearance issues with the chassis brace), loosen (but don't fully remove) the 3 bolts and 2 nuts that hold the OEM exhaust manifold in place
5. Set the parking brake and chock the rear wheels. If you don't have access to a lift, use a good floor jack to raise the front of the car (there is a jacking point centered about 12" aft of the front bumper under the car). If using a floor jack, after raising the car about 10-12" off the floor, place jackstands underneath the jacking points on the sides of the car and lower it onto the jackstands.
6. Put on some safety glasses, then crawl underneath the car with your breaker bar, a socket wrench, a crescent wrench, a small plastic bowl to keep track of the parts that you will be removing and replacing, and 12mm and 14mm sockets. It's probably a good idea to take some socket extensions with you too.
7. Using the crescent wrench (or spanner, if you prefer), loosen the 02 sensor, which you will find just on the left side of the header immediately fore of the flex pipe. Remove the 02 sensor and then use a zip tie or something to secure it out of the way while you remove the header.
8. Remove the (3) 14mm nuts securing the manifold to the catalytic converter.
9. Remove the bolt that secures the exhaust manifold bracket to the engine block.
10. Remove the 3 bolts and 2 nuts that secure the upper portion of the exhaust manifold to the cylinder head.
11. Separate the lower portion of the exhaust manifold from the rubber hanger (near the catalytic converter)
12. Pull the manifold away from the catalytic converter while supporting the upper portion. A helper from above may be useful.
13. Pull the upper portion of the exhaust manifold away from the cylinder head (and clear of the 3 bolts protruding from the head), and then carefully drop it down from the car.


DC Sports Header Installation


1. Inspect the original exhaust manifold gasket and replace it if it is damaged.
2. I should have thought of this earlier myself, but to protect the finish of the header, wrap the header in some old T-Shirts or towels and then secure with masking tape or elecrical tape, being extremely careful not to let the tape actually touch the header at any point - just wrap it around the shirt or towels themselves. This will help protect the finish when you fit the header through the opening underneath the car.
3. The included instructions call for the header to be installed in two pieces, but I believe it can fit as a single piece. I didn't try it that way, but after installing another (1-piece) header, I found it much easier to handle it as a single piece. Be sure to insert the included gaskets when joining the upper and lower portion with the included bolts. (If you successfully install a DC Sports header as a single piece, let us know and I will update the article.)
4. Once the header is lined up properly with the head (make sure the manifold gasket on the head side is properly aligned), torque the nuts and bolts to 33 lb-ft (some may be easier to reach from above). If you are installing the header in two pieces, the job is much easier if you have a helper holding the upper portion in place from above.
5. On the catalyst side, torque the nuts to 25lb-ft. Don't forget to insert the 3rd (included) hard O-ring gasket between the cat and the rear flange on the header.
6. Install the 02 sensor into the bung on the DC Header and torque it to 33lb-ft.
7. Remove the protective padding from the header and then clean the header as well as you can. Double check all of the connections.
8. Lower the car off the jack stands
9. Start the motor and listen for any signs of exhaust leaks. If all sounds well, take it for a spin and enjoy. If there is definitely a leak, don't drive the car until it is identified and fixed.

(http://i35.photobucket.com/albums/d199/7thGenVillian/tov_ahc6016-06.jpg)
(http://i35.photobucket.com/albums/d199/7thGenVillian/tov_ahc6016-07.jpg)
(http://i35.photobucket.com/albums/d199/7thGenVillian/tov_ahc6016-08.jpg)
(http://i35.photobucket.com/albums/d199/7thGenVillian/tov_ahc6016-10.jpg)

Courtesy of TOV.

nice DIY only i have an issue. and rather than start a new thread i thought i should post it here.

anyway my issue is that i have stripped the heads to one of the bolts that holds the stock exhaust manifold down. and i have no freaking clue of how im going to get that sucker out of there. any suggestions? maybe cutting the thing out? if so what should i use to cut it out? then if im going to have to cut it out of there, what kind of a bolt should i put in there?

oh and i stripped the bolt head. just to clarify. lol i haven't gotten the thing to budge, thus the head stripping.

^ the same thing happened to me, i ended up having to bring it to a garage and have them do it. They did it, and charged me an arm and a leg

Uhh ohh.  You're kinda fucked RJ.  The only thing I could recommend is a bolt/stud puller before going to a shop.

yeah i can get the 2 nuts and 2 other bolts off and loose, but one is stripped. so im having a shop remove the one bolt and replace it with a new one...thats not cemented into the head lol.

can anyone enlighten me on the diameter of the front side of the CAT ?

the flex pipe coming off of the DC headers is a 2.0" opening.... how will this match up with an OEM I4 CAT ?
is it smart to get extra bolts in that area?
knowing my luck i'll snap one and be screwed....

also have been pricing the magnaflow high flow CAT ($110).... which has a 2.25" opening (which i wanna make all my piping 2.25")
would this just be an expander flange that could make the conversion from a 2.0 to a 2.25" ?

The DC header is designed to work with the stock cat, so there shouldnt be any problems with fitment. As for the bolts, there spring loaded. I dont think they have a tendencey to snap seeing that there is some give to them. The only thing i can say about the aftermarket cat is that DC will not honor the warentee on their product if its used with an aftermarket CAT

stock exhaust piping on my I4 is 1.75"

obviously this starts after the CAT...
meaning the oem CAT has 2.0" inlet and 1.75" outlet?
or does the outlet reduce down to 1.75" from a 2.0"?

trying to get it all figured out to how i wanna do cat back exhaust with the headers+cat setup
sounds liek all i need is a couple of gaskets then
parts 14 and 15 in this link
http://www.hondapartsnow.com/Page_Produ ... appid=8383 (http://www.hondapartsnow.com/Page_Product/PartDetail.aspx?catalogID=64&productID=5&yearID=21&doorID=4&gradeID=8&areaID=2&transmissionID=7&originID=-1&colorLabelIDs=-1&colorLabelID=-1&sectionID=5&idAndImageID=11587%20465481&refNo=15,14,4&isBigPicture=True&pageName=&appid=8383)

hey i stripped one of the nuts that connects the flex pippe to the cat.... what do i do ?

everything else was flawless.... just that one fucking bolt ! GHQJHOWXOLQ ahhhhhhhhhh
so pissed.... i was so damn close...

what should i do ?
does that bolt pop out of the cat flange??
or do i need to somehow get it off and get a replacement nut?

or shoul di just go magnaflow 2.25" high flow cat?
hows that work when the flex pipe off my dc header is 2.0" ?

thanks all

perhaps this: thoughts?
http://www.speedycarparts.com/sku/Honda ... 0400207488 (http://www.speedycarparts.com/sku/Honda_Accord_Eastern_Catalytic-Converter_2003_2004_EAST40400.html?ci_src=14110944&ci_sku=00012000540088203_0400207488)

or just get part number 3 on this:
http://www.bkhondaparts.com/billkay/jsp ... T+PIPE+(L4 (http://www.bkhondaparts.com/billkay/jsp/prddisplay.jsp?catcgry1=ACCORD&catcgry2=2004&catcgry3=4DR+LX&catcgry4=KA5AT&catcgry5=EXHAUST+PIPE+(L4))&ListAll=All&vinsrch=no&systemcomp=Electrical%2FExhaust%2FHeater%2FFuel&prdrefno=&quantity=0&act=&count=0&hidSwitch=&hidIrno=

$8 bucks a bolt.... might be a HUGE pain in the ass to get out of my severely rusted flanges between flex pipe and cat...

bump....

was anyone ever able to get one of those bolts out of the flange between flex pipe and cat ?
stripped a nut and dont know if i should juust try to have a garage take it off
or just invest in high flow cat and cut the damn thing off

heavily rusted together

What kind of tools are you guys using to strip these nuts?
In my past experience cheap sockets always stripped nuts and more expensive ones usually get the job done.

I also found that soaking the bolts in a little WD40 helped to break up a little bit of the rust and make the job eaiser. Carefull not to get it on your tools or youll be banging your knuckles into the header

all sockets were Kobalt... not the best i know... but also not some no name brand
shit sucks... i cannot believe the amount of rust in that area...

i want to just cut the nut out... but im affraid i wont be able to get the flanges apart due to the rust problem
depbating just getting a whole new cat since i wanna do a 2.25" piping, 18" magnaflow resonator to a 2.25" piping... to a 14829 magnaflow muffler
just wanted to take it once step at a time and not just go drop 600-800 bucks

hey guys just got my DC Sports headers installed on my I4....i notice some nice power and smoothness increase....sound is a little different, haven't quiet diagnosed it fully
get the old sawzall and PB Blast out and kicked my cars ass.... lots of cuts....very dirty...prolly dont smell too hot either...but its done...sorta

question, my O2 sensor does not reach far enough to connect to the downpipe of the lower header piece... i need like another 3-5 inches to be able to screw it back in properly

has anyone else had this issue?
i have the part number for the o2 sensor.... just not sure what the actual connections are (4 wire ?)

http://www.2kracing.com/Product/2720.html (http://www.2kracing.com/Product/2720.html)
this seems like it would be perfect... not sure if it will fit, says Honda... kinda too general for me to spend the $18 + shipping

let me know what you guys think, for now i unplugged it and kept the 02 sensor screwed in so it doesn't sound like a lawnmower.... bagged/taped off connections for water prevention
thanks

also heres a few before and after pics for those interested in the difference between our OEM headers and DC Sports Ceramic Headers

top shot before install...no heatshield
(http://i472.photobucket.com/albums/rr89/winndogg34/Headers/P1020045.jpg)

comparison of the 2...different flow path/distances
(http://i472.photobucket.com/albums/rr89/winndogg34/Headers/P1020054.jpg)
(http://i472.photobucket.com/albums/rr89/winndogg34/Headers/P1020055.jpg)

downpipe comparison
(http://i472.photobucket.com/albums/rr89/winndogg34/Headers/P1020048.jpg)
(http://i472.photobucket.com/albums/rr89/winndogg34/Headers/P1020052.jpg)

notice on that last pic how far the 02 sensor location moved.... sucks...

im really thinking thats the exact piece i need...anyone agree/disagree?
if i dont hear back i'll call the number tomorrow and ask questions...order it asap

Wow I didnt know that the hole for the O2 sensor was moved that far down. Is there any kind of adaptor available for the O2 sensor?

sheesh, i didn't realize how much one of these things costs...

oh well, maybe it'll be my next mod if i can save up the money.

can I do the installation on ramps? lol

sure... just make sure those ramps are high haha... there is alot of under-the-car cranking and dissassembling that needs to be done
 i had mine on uber high jack stands....scary as shit to tell ya the truth

its more of a comfort thing.... even what i had wasnt enough... it was intense under the car like that, not much room at all...

start PB Blasting your connections now.... the downpipe connecting to the CAT.... those 3 bolts are a BITCH...lemme tell you....

haha yeah I just bought a car of PB blaster from walmart FTW. I also found out my car is way too low for the ramp. So I guess I gotta jack stand.

OMG F the header installation. 2-3hr my ass took me 5hr. lol I am all cut up and stuff. Thank god for PB blaster and 3 1ft extension + 1 6in extension, and 18in breaker bar, and 3 jack stand so I can place the extension on it. The Cat bolt were a bitch to get off. Had to make an extension all the way to the front of the car so I could move it since I didn't have leverage while I was under the car. Also that one bracket that connect the motor to the car is a bitch also. I wanted to cut it off since it was soooooo hard to get a 3/8 under there to break it free.

Overall, Great mod I can feel the low end tq come back. it wasn't as good as the pulley but its pretty good. Also it smells right now I think because all the pb blaster and stuff is getting burnt off.

Another thing does the car make a whistle at like 3k+ I looked at the header before I installed them and the welding looked shitty for DC headers. There was chips inside of both of the tube that goes 4-2. The 2-1 the flange was welding kinda sideways like 1-2* off. O well it was a fun experience. I will never do it ever again lol

for those who do this install and have the issue with the o2 sensor wires being too short to reach the new hole, you can extend the wires using butt connectors(i think?). my brother just installed an X-Pipe on his mustang gt and needed to extend his o2 sensors and he did it that way. so far no CEL.

I'd refrain from using butt connectors on something like that. At the minimum, solder the sensor wires to the extension wires and heat shrink the individual followed by heatshrinking over the entire assembly. An o2 sensor is not one of those things you want fucked up by the elements.

There is an extension that you can buy from DC or Casper Electronics.  As for using butt connectors, well, it's a bad idea.  Don't expect that to last without ruining your sensor and possibly causing a fire.

my headers came with the extension cable. If not you can order it. Its 15 bucks + shipping. I can't remember where I found it.

I got mine from whoever bought DC from AEM.  I think it's Pilot.  Casper electronics has them too.

Hey guys, I'm in the process of getting the header installed, and ran into some bad luck right off the bat. Of the 3 bolts that secure the heat shield, the top two popped off like nothing, but the lower one was seized, and after an aggressive negotiation with a pair of vice grips, the head of the bolt is rounded (stupid, I know). Gator sockets won't touch it, so before I decide to take it to a shop, I had a quick idea I wanted to run by you guys. Since it's the lower bolt, can I just bend the heat shield backwards and proceed with the install, or does it have to come off?

If its the heatshield you're having problems with while removing the stock manifold, just rip that shit off. You don't need it. Tin snips, dremel, bending it back and forth until it breaks, whatever it takes. If you're trying to put the heat shield back... why?

Just trying to get it off.. Thanks man.

No worries. I'm one of those that breaks shit off if its in my way and I don't need it.

I just installed the headers and was wondering if that whistle is normal? Engine makes an annoying whitsle when a press throttle moderately???

I did some research and apparently the o rings are pretty crap. I think I was the lucky one and got a bad o ring, which doesn't make a perfect seal. So I will now have to order some o ring gaskets. Boo
Edit: I don't know if it might be the flex pipe or just a bad o ring. Do you guys have any suggestions on how to diagnose the problem area?

with the car running, spray a soap/water solution on the possible problem areas to see if there is a leak

Ok thanks I will try that, hopefully this weekend.

The other thing that you could do is get a mechanic's stethiscope and use that in the area where you suspect the exhaust leak.  That's what they use at most exhaust shops.  Hopefully it's the o-ring gasket though.

Today after I changed my spark plugs, I went and checked my header to see if anything was loose and found one bolt near the top of the motor loose. so I tightened it. All other nuts and bolts were secure. So I thought that one loose bolt was the culprit of my problem. But after taking a test drive the hiss was still there. So I will to try something else. I don't have much time to be going to a mechanic shop. Soo, I was thinkig if I can grab exhaust tape and wrap the flex pipe in it. Then hopefully I can narrow it down to two things: If the hiss goes away then I know it's the flex pipe. If the hissing remains then it would have to be an o ring gasket. what do you guys think?

p.s can i even you use any kind of tape just to take it around the block to test it?

So post header install, after a few minor issues, my car sounds very very raspy at low RPM's. I'm not sure what could be the culprit other than a loose bolt (no whistles, it's just raspy as hell), OR the fact that the rest of my exhaust is still stock, and the stock equipment just doesn't sound good with the extra free'd up airflow. Also, my cat is SULEV... not sure if that has anything to do with anything. Car is a i4 AT. Other breather mods include Fujita CAI and TSX IM.

Where is the "raspy" noise coming from?  Your muffler, or around the header?

I *think* it's coming from around the header, because the sound is amplified when I'm next to other solid objects (i.e. other cars, dividers, etc.). Another thing I should probably mention is I'm still using a broken o2 sensor. My original fell out and got destroyed. I don't think that has anything to do with it, but I have a new one coming in the mail so I can finally get rid of this CEL.

Do you have anything plugging the hole for the primary a/f sensor on your header right now?

yes, the broken one, so it doesn't sound like a ride-on lawn mower (there's no mistaking the sound when that thing pops out). now it only sounds like one of those push mowers.

From the description, it sounds like a bad leak from one of the junctions and not the flex pipe. You might have a blown gasket or that o2 sensor isn't plugging up the hole very well. If you were to lay down next to your car and listen for it, it'd help you and us determine what the problem is. Another question I have is if there are any mods to the stock exhaust (I.e. removed resonator) or is it unmolested?

The stock exhaust remains unmolested..

You're first task is to try and determine if the noise is coming from near the engine or near the tail pipe, then we can move on to phase 2.

(http://www.animecutie.com/gg_data/images/7/smiley-sign-im-with-stupid-5037.gif)

It's definitely closer to the engine, tail pipe doesn't make much noise at all actually. When I crouched down and took a look while the car was being revved, the cat itself seemed to have a good bit of "movement" to it. Dunno if that's normal or not. My new o2 sensor is going to be here Monday or Tuesday, so that will help eliminate that problem..

After you replace that, give it another try and see if you still have the noise.  It could be a cracked flex pipe also.  That's what I'm dealing with right now.  I'm having to get mine replaced a 2nd time.

Thanks Tim.. In the meantime, what are the obvious symptoms of a cracked flex pipe? When I did the install, I did notice the slightest little rip in the end of the FP (obviously, CAT side), amounting to no more than a millimeter in length, so I figured it was fine.. I wish I could record the sound of this to give you guys a better idea of what's going on.. and perhaps some better diagnostics.. There's a chance I didn't torque the cat bolts correctly as I just did it by feel.. it's hard to imagine what else could be going on here...

If you noticed a tear, and the fact that your engine moves a lot, my guess is that over the short period of time it's gotten worse and that's causing the noise.  I'll bet you $100 that it's your flex pipe if you still have the noise after you replace your O2 sensor and torque your cat bolts.

OK, so here's the latest. Got the o2 sensor in the mail yesterday, and I installed it today. Disconnected and reconnect the battery, and that cleared the CEL, HOWEVER, I crawled under the car and put my hand around the o2 sensor area (tight as hell w/ vice grips) I felt hot air blowing. The weld directly next to the o2 sensor looked a little shady, like there was what appeared to be the smallest of cracks in there. I've attached a pic (best I could get with my phone) to show you what I'm talking about. Check out the weld directly to the right of the o2 sensor:

http://i80.photobucket.com/albums/j164/ ... stleak.jpg (http://i80.photobucket.com/albums/j164/frostnyc/exhaustleak.jpg" onclick="window.open(this.href);return false;)

Also, when I first started the car you could see smoke flowing around the flex pipe area. It's one of three things I think. The o2 sensor threads got stripped, so it's just not sitting tight, the weld in the photo is forked, and I need to take it in to have it patched, or the flex is shot. As always, your help is appreciated guys.

Hard to see if it is cracked... you might have stripped the threads taking out the old 02 sensor, I know I did when I changed out mine. I had to rethread it and the o2 sensor sat fine. No problems since. Btw your flex pipe is clean as hell...

*Next time use the [img] code from photobucket so the picture loads up!

That's definitely a possibility. I screwed the new one in already, and it sits flush, and still "turned" while screwing it in, but it took a good amount of effort getting it all the way down. I can't rule out that the threads on the header aren't stripped, I just know it has to be stupid tight for it to not fall out. I thought it was tight the first time and it fell out on me. When I re-screwed the broken sensor in, I made sure it was in good. Same today when I replaced it with a new one. I figure my best bet is to take it to an exhaust shop now and see what they say because there's definitely a leak somewhere. Again, I noticed grey smoke swirling around the flex pipe area like the flex pipe itself was haunted immediately after the car was turned on, it stopped about 2 minutes later. The hot air I felt was flowing from right the area around the o2 sensor, so I'm trying to figure out if the o2 sensor hole there has a leak, or it's the weld next to it.

I'm reluctant to think it's the flex, because it DID NOT sound like this (which was later diagnosed to be a cracked flex pipe):

http://s36.photobucket.com/albums/e25/n ... I_4514.flv (http://s36.photobucket.com/albums/e25/nexson1/?action=view&current=MVI_4514.flv" onclick="window.open(this.href);return false;)

What's involved with rethreading it? Do you have to take the whole downpipe off?

OK... well asfar as the rethreading is concerned they sell a tool set and you can do it yourself OR the shop can do it for you! You could possibly have a leak if your still get smoke swirls around the flex pipe. Take it to the shop and have them check it out for you...

OFF TOPIC for a sec....

Where in NYC you from...? Chime in on the NYCM squad thread HERE (http://elitecm.net/forums/viewtopic.php?f=58&t=241) plus there is a bbq meet up in CT you can check out HERE (http://elitecm.net/forums/viewtopic.php?f=58&t=2840)

Hope to see you at some meets dude! Get to know your fellow members...

Yeah, I plan on taking it to a shop next week. The good news is, when calling around for estimates, I was referred to this small custom exhaust shop by a regular garage (which I've been looking for for a while, they don't exactly advertise in the yellow pages).. and he has a mandrel bending machine (which noone else around here seems to have), so when I do my exhaust, I'll probably go back to him, provided he does good work and gives me a fair deal.

**** Question.. to rethread the hole for the o2 sensor.. Do they have to take off the downpipe? I suppose it doesn't matter. If it needs to be fixed, it needs to be fixed. So sick of spending money on this damn install.

As far as NYC goes, I used to live on 34th and 9th in Manhattan for nearly a decade.. then moved back to LI to finish school. I still DJ in the city Thurs - Fri - Sat. Would love to come hang out, but I work Saturday's man.. gotta be spinning by 10.

From what you've described, I'm guessing it's the flex pipe.  You should go to an exhaust shop and have them find the leak and fix it.

Nah the pipe dose'nt have to be off to rethread, having the ride on a lift would be easier for sure but since you getting that leak fixed they can do it without a problem since the pipe has to come off.

We do meets during the morning/day you can be back spinning records don't worry lolz... make a profile HERE (http://elitecm.net/forums/posting.php?mode=post&f=4) so we can see your ride! Good luck with your fix man...

Done, and thanks man. I'll report back when everything is fixed and let you know what it was..

No doubt, we are all here to help!  

Someone get that man a cigar....

Went to the shop today.. and it was indeed the flex. He made it a point to tell me I got the o2 sensor in there "real good.." lol..
Car sounds much better. Thank you guys!

Now, where's my money?

Go Comptech Headers or go home.     Them are bad mamma jammas.

I've done some reading on k20a and those guys aren't fans of Comptech headers either. I can't remember why though. Might be because they're an off the shelf header like DC but don't quote me on that.

You've also got to remember that a lot of those guys are building race cars.  Their motors are built from the ground up using mostly, if not all, aftermarket internal.  An off the shelf header is not suited for fully built race motors.  The Comptech header is good for a car with bolt ons and is an upgrade compared to the DC header.  I doubt there are may people here that are worried about proper header or exhaust tuning, let alone even know what that is.  In all honesty, there are only 3 or 4 guys on here that post regularly that have somewhat built motors.

A lot of them do build race cars, true. A lot of them also DD these setups and usually run Hytech headers which are big money. Yeah, the Comptech headers are a step up from DC but also a bit out of the price range of a lot of people here. Also, a lot of the DD big power setups those guys run are actually on OEM internals as opposed to aftermarket. Granted, the internals aren't stock to the motors they run but that's discussion for another thread.

Well, here's the thing.  The Comptech headers aren't a much more expensive than the DC when you compare the price difference between the Hytech, SSR, J's Racing, or Toda headers.  The only ones that are reasonable, are the K-Tuned budget headers, but those are swap headers, and may not fit our chassis.  Someone would have to buy one and see if it fits our chassis first before I would blow the loot on one.  I'd rather take the safe road and make sure it will fit our chassis with something developed for the CL7 or CL9 instead.  Too bad those headers are like $1200 to $1500.

can someone tell me if the bolts on the head of the engine holding the exhaust manifold on snap easily? how can i prevent them from stripping or snapping

Mine broke without too much muscle, no pb blaster, but I realized after the project that two nuts were basically locked on their bolds, so they came off like the rest of the bolts. If you're pulling with all your might, you'll probably strip something, so just use your best  judgment.

damn after reading all this im kinda reluctant to buy the headers...

just curious, my boy has a dc header from his 05 tsx motor...wud it fit on my 07 k24a8?

Yes and it will also stick your exhaust out further. The tsx header is longer than the accord header.

Cool thanks bud, I'm getting a custom catback so I'll lose the extra length there

I understand this thread is old, but  believe it or not after reading it I kind of got more confused. I just want to clarify some things if you guys don't mind. The car is an 04 K24 accord sedan, and I'm hoping to install TSX aftermarket heads. So what I'm not too sure about is the following:
The headers will bolt up fine, but they are too long so you'll need a shop to cut and weld? But where exactly will they need to cut and weld.
You will need an 02 sensor extension?
Comptech is the best brand to buy?
Can you reuse any gaskets or will I need to buy new ones.
If everything else regarding the exhaust is stock can I do this mod, or will I need other exhaust parts as well. Only mods I have are the TSX IM, K&N intake and Intake resonator delete. 

Thanks guys, looking forward too and I appreciate all the potential answers.