Now to top it up of my previous post yesterday.

1. Replaced part 9 with polyurethane and they hold the fujisurbo much more firm. The critical No 9 piece is actually the centre piece that is in the middle of the car. It takes most of the weight. The side triangle rubbers, I could not replace as I have not found the polyurethanes ones yet. So far, seem better now. No more side swings.

2. The 4 pt cusco. I had to take it out and bend the side flanges. Also put in an inner washer on both sides, so that it acts to prevent complete bending upwards again. The front rubber, added a folded stiff rubber sheet to raise the rubber upwards and allow the rubber to sit back. By doing so, it raises the exhause upwards by about another 5 mm and this helps to clear the cat cover. No more sound for time being.

Also did my CAI today with a rubber scoop. Self made stuff and also installed the mugen grill. No more honey comb Euro R face, going for the naughty look...

my rattle got worse now. it rattles whenever i stop in traffic. also rattling varies depending on temperature and it seems to get worse during hot temperature.

yeah when i bring it back to the shop i'm telling the mechanics that if they can fix it cool, if not i'm putting on the stock headers again. the performance gain in my mind is not worth it. i'll just be content with my injen CAI and reflash.

Just today, I had the rattle back as the cat cover hitting on the cusco 4 pt. Finally, I had the whole fuijisurbo exhaust raised as there is more than enough space to do it. Not, it has the cat cover 1 inch above the cusco 4 pt. Finally, no more rattles and it also feels the stock header seemed more firm as I don't get a leak on exhaust running in my aircond during vtec now...

i think your rattle is just from cat banging on the cusco brace. i have the cusco type2 brace too, but my cat is not touching the brace at all. its just a whole different rattle noise.

performance gain with comptech header is so great that its really hard to give up. but if this can't be corrected, i'm gonna switch it back to stock too. its just too loud and annoying to have crappy rattling noise..

one thing i noticed was that rattle dissapears if the rpm was increased very slightly (around 100~200 RPM). if there is a way to increase the idle point to about 800~850 RPM, this rattle will go away.

Oh I see. Your rattle is not the cat cover on the cusco. One of the thing that I forgot to mention is that there wqas a rattle from the cat and there seemed another rattle at the lower part joint from header. Happens especially when letting go the acclerator suddenly. I also had exhaust coming through my aircond ONLY in VTEC zone. AFter raising the whole exhaust, it has gone away bothe rattles. I suspect in your case, check your 2-1 flex and also the connections.

Funny that most of u that had installed the header has the same issue. Maybe you guys can try lowering the exhaust a little and see if the flex hose force is reduced. Maybe the rattle is coming from there.

Just a hunch...

Well, 2 ways :

Option 1 Have a piggy back and retune idling higher. I think if you have Hondata, it can be done already.


Option 2 : Cheapest and easiest. Locate the acclerator cable in the engine bay and have it tighten such that it pulls the accelerator a little or at the end of the accelerator turning holder, see if you could prevent from going all the way back, thus raising idling speed....

I replaced the headers hanger no more rattle in the front of the inside cabin just very mild vibration in the rear. Towards the exhaust.

Before that hanger was tore and the car pretty much shook with the idle in drive mild and then the ac compressor it shook even more.

thats promising news, still haven't had a chance to swing by the shop that did my install to have them take a look

so did you just cut off the existing one and replaced it with the new hanger? do you have the picture of new hanger so that I can see the location of the new hanger?

oh.. wait.. are you talking about the rubber hangers?

Yea its that rubber hanger that you see, my stock one was torn up and caused alot of body shake when the ac compressor came on.

Now its very mild, the exhaust system still makes the car shake from the rear.

Just for reference of the rubber hanger in normal position.

they are really stratched up with comptech header. need for relocation for the metal hinge?

The fix is easy. Just cut the Comptech hanger off the flange cleanly. Then weld it back up on the flange a little higher.

Just installed Comptech's header and I noticed this inside ten minutes, when I came to a stop sign (A/C off). Playing with it for a few minutes, I notice it only at ~700 rpm (5AT). I wouldn't describe it as a rattle - in that being a metal on metal clank - but, more of a low frequency oscillating hum. If people feel differently about that, then possibly I have a different problem, but I don't find that highly likely. I left it in drive with the emergency brake on, walked around the car and looked under the hood. Everything I could see vibrates a bit, but clearly isn't hitting anything. I could however hear this hum quite distinctly near the mufflers - driver's side seemed more pronounced, but maybe not, hard to tell. Not saying that's where it's coming from, it could just be that it's the farthest point from the engine and doesn't get drowned out.

Well, I found my rattle. I was checking JTso's pic vs mine to see how my header hanger is stretched, I accidently brushed my finger against the heat shield right above the cat. It is 100% the same noise. However, nothing is touching it, not even remotely close. So I can say my rattle, for all of its inconsistency is harmonic resonance from the heat shield and exhaust (well primarly the car's natural vibration).

Still bothers me though that my header is pulling down on my hanger that much. Wonder if Comptech would care to see that?

Could someone with an OEM exhaust and a Comptech Header please post a shot of their hanger too? I would like to see if it is just mine or a common thing. I could have my Comptech exhaust pulling it down that much.

i think we need a extra hinge on the middle portion of comptech header that hooks into stock hold down bracket to reduce excessive vibration.

I'm not so sure that would make a difference. The DC one does not even though it is a 2 piece design.

Here's a picture of mine with the stock exhaust. Fortunately, I do not have a rattling issue.

looks like yours is stratched a little, but not much as the other picture. i think my hangers are stratched as much as moda's.

I dropped the heat shield today (around the cat) just to see if it would make a difference after you posted this. Unfortunately, it didn't, I experienced the hum without the heat shield. Putting it back it, no difference that I could detect. Since I have an automatic, I put it in drive with emergency brake on and watched as the rpm slowly decreased from startup to idle. At 1000 rpm, the header-cat-exhaust almost doesn't move, 900-800 rpm, there is a slight vibration, but at around 700 rpm it vibrates like mad and I can clearly hear the sound. Almost seems as it's behaving like a tuning fork. Given all the other rattles I have, I can probably live with this as there is a noticeable benefit, but it would be nice if this could be solved.

Here's a pic of my hanger (stock cat, exhaust) and it seems to be a little stretched.

I think you have a same problem as me. Car gets pretty rough at 700rpm, but this noise dissapears with slight throttle tip in to around 800rpm. I'm gonna try relocating the hinge on the header and see if it will help the vibration.

THANKS!!!

Looks like my exhaust is pulling it down some then. I'll have to make some adjustments and maybe even get a new hanger since mine seems so stretched.

Try giving the heatshield over the cat a little adjustment too.

what if we put some poly bushings in between the mounts for the heatshild?

I'm not sure if it is the shape, mounts or what because the resonance is causing it. Only way to know is to try it at this point.

You could try sandwich the under carriage heatshield mounting bolts with soft washers (leather material from hardware store - plumbing dept.) and see if that solves the resonance problem.

removing the heatshield completely is a bad idea i guess huh

It could be if you are sitting in traffic a lot.

is it easy to take off once under the car, can i remove the heatshield without removing other parts?

that way i could atleast test it out to see if that is what is amplifying the sound

Yeah, it's easy, takes about five minutes. Four bolts and it's lightweight, flexible aluminum which can be slid around (go towards the driver's side) the cat/exhaust without damaging it.

Like I posted above, I removed it yesterday and it didn't make a difference. However, try it, maybe we aren't experiencing the same thing or maybe you'll notice something else while under there.

i think we are in agreement though that the heatshield if anything is just magnifying the sound of the header rattling and is not the main cause.

spoon did u call comptech?

There are only 3 other failure points on the header then... the flange at the block, the flex pipe and the flange at the cat. There is nothing inside the header that is going to rattle. Reach under your car and just pop that heat shield with your finger nail, just enough for it to vibrate. See if that sounds exactly like the noise.

i dont know if anything is failing but instead just shaking more as a result of the design compared to oem

thats what i think too. not much absorbtion of vibration compared to oem header. comptech didn't had email address for tech support, so i just sent them email to sales support email address with links to this thread and ones from tsxclub.com. if we call them, they just say to send back the header for a check up..

I found that my Comptech SS exhaust was vibrating and hitting heat shield #28 (???) near the resonator. I bent the heatshield slightly up, against the cab and the noise has greatly deminished. I also slightly over-torqued the clamp holding the two straight pipes together and now the sound is almost gone.

I suggest checking the top of the exhaust from the cat back to the mufflers for any sign of contact. There is still a slight harmonic rattle but it comes and goes.

Hope this helps someone.

so do you have a comptech header too?

Yes. Didn't happen till I put in the header. I have a previouse post in this thread with more info.

No, I just swapped the header this past Saturday. Noticed the vibration basically right away, but it's weird, yesterday too, I could hear it if I got stuck at a long light, but today not so much really.