Hi,

I just got my Comptech header installed on Sat. The first day it feels ok, but the 2nd and today, when I step down on the gas, I can hear a metal flapping sound. When I hold the gas padel as steady position, nothing can be heard. When I put on parking and step down the gas let the rpm goes to about 3k rpm, nothing can be heard. It only happens when I step down on the gas. I cannot really feel the rattle, and cannot really pinpoint where does the sound is coming from.

I heard Comptech as no problem what so ever, what's going on????

BTW, how do I tell if I have a leak or not and is it necessary to retorque the bolts after a week?

Many thanks.

 

Tighten all the bolts down again. Especially where the downpipes meet the manifolds. I'm guessing you either have a loose bolt/nut, or they are not tightened all the way, creating a leak.

 

Hmmm...I'm no expert here so I really couldn't tell you where the flapping may be coming from. I installed my headers and had no such sound. As for re-torquing...I don't know that it's necessary but it's definitely a good idea. I did mine twice after I installed them just to be sure. To find a leak, I would jack the car up or put it on a lift (make sure it's securely supported) start it and just move your hand around the headers and the rest of your exhaust. If you have a leak, you'll feel the exhaust on your hand. Be careful, those pipes heat up quicker than you might think. Sorry I couldn't be more help but I hope you get it taken care of.

 

Thanks, what's the torque spec you suggested?

 

The torque for the bolts connecting the headers to the A pipe should be 40 lb-ft and the torque of the nuts that hold the headers to the block should be 23 lb-ft. Those are the numbers for the stock headers that I got from the Helm's manual but I would think that they would work for the new headers to. That's what I used and I've had no problems so far. Good luck torquing those back 5...I know I had a heck of time.

 

Thanks everyone, I will schedule a retorque service this weekend.

 

also check the bolts that hold the catalytic converter heat shield sometimes they will loosen after you install the header

 

Isn't the heat shield gonna go away for aftermarket header. I got 2 heatshields but cannot see the 3 holes for bolts like the stock one has???

 

Ooops, I saw it's a "catalytic converter" heat shield not the manifold heat shield. Is the catalytic converter where the A pipe connect to?

one more question, are downpipe and A-pipe the same thing?

 

take the cat heat cover off.
guarranteed thats what it is rattling.

 

Joseph, it that going to cause any problem??

Does everyone take it off?

 

not sure about everyone.
but the cover uses small bolts that rust.

i took mine off.
i posted a thread about it.
somewhere.

it wasn't obvious.
when i tapped the exhaust pipe near the 02 sensor and it would sound like that rattle was elsewhere...further up the collector pipes.
but it was the cat cover.

if you're buggin...get it replaced.

 

I triple hose clampped the cat heat shield and still rattle. I took it to the local mechanics and found the rattle is coming from the downpipe at the weld where the 3 pipes meets. Is it a common problme?

How can I solve this problem? Return/preplaced from Comptech? or anyother easy solution.

Need help please. Thanks..

 

did you take off the cat cover?.

at least try it.
i'm not sure hose clamping it will work.
there isn't much in the downpipe and collector pipes that is going to rattle.
my money is on the cat cover

 

ok, I think you're right. I just have my brother helped on the padel I looked down under the car. The sound is coming from the heat shield area. I dont know if the leak blow on the heat shield or it just rattle itself. Need to take it off or got replaced soon.

 

Retorque all bolts, o2 sensor, cat heat shields, exhause, exhause tip....for $15.....now no more rattle. love my comptech more. thanks for everyone's help.

 

the little nuts that hold the cat cover together are crap.
the install itself will break them loose.

rip it out.

 

guess i live dangerously & or am a lazy bastard. When i did my comptech header install over a year ago, i tightened the shit out of all fasteners as i didn't want to perform the retorque. Some of the fasteners you damn near needed to be a contorsionist to get to, on the firewall side. To this day i have had no problems. I was thinkin about using loctite (red), but i figured the extreme heat from these puppies would disapate the loctite rendering it useless.