i am thinking i need a new cat anyway, so should i buy a new stock one, or a carsound (or other aftermarket)? will i gain high end power at the expense of low end?

here are the symptoms... after getting my header and exhaust piping installed, the car would make a funny noise around 1500 rpm when the car was first warming up. a rattle of sorts. it would tend to go away after time.

i saw when they took off my old b-pipe, a bunch of little rust pieces slid out. it was thought that similar stuff had accumulated in the cat, and when i start up cold, that material is rattling around in there. once the car warms up and the cat starts doing it's job, the material sticks to the walls(?).

but the nature of the noise makes me think it is something rotational (flywheel maybe?)... like it makes the rattle, then slowly fades away.

i will likely be upgrading my clutch/flywheel in the offseason as well, so if that's the problem, it should get sorted then.

advise on the cat is still appreciated. thanks,

-phil

 

Are you sure its not just a heat shield? That's a very common rattle problem for integras. I'd say its probably not worth upgrading your cat, you will get very minimal benefit from it. And I hope it's not your flywheel because rattles in things that spin at 7000+ rpm are bad news.

 

what does the heat shield look like, and where is it located? i'll take a look to see if that is the problem.

i wasn't sure of the flywheel, just thinking of what's rotating that could make the noise. any idea why the noise only happens at 1500 rpm?


thanks,
phil

 

got the same noise...turned out to be bent heatshield rubbing. got bent when I installed my cat-back. just banged the dent out, e'rething is cool now.

 

where is the heat shield located?

 

My problem was that the heatshield was so rusted it decided it no longer wanted to associate with the bolts holding it on, so it was just bounding around all over the place. It was the cat heat shield btw. I just ripped it off!

 

It surrounds the cat. There is a top and bottom part and they are attached by 4 bolts. Actually, I think the top part is attached to the car somehow. Anyway, chances are that this is what is making your noise. Mine rusted out one bolt at a time. After the first two it rattled a lot so I bent it down. When the 3rd one went it was just draggin on the highway until I pulled over and yanked it off.

Here is a pic:



Item 5 is the bottom and 6 is the top. You can get both for around $45 from Acura Carland online, but IMHO they are not necessary. Just be careful where you park (i.e. not on dry grass, etc).

Mike