rattling at 3k - 4k
 

yeah got a 95 civic ex stock header and everything and a have a rattling sound around in the cat. area dont ,know what it is. and its not the heatshield on the cat. either something else. help please.

I guess It might be the inside of your cat. The pellets.

by the sounds of it, i had the same problem....its the gasket in the cat. between the downpipe and the cat. check in there...it should be lose...mine was atleast.

Also, check if the connection between the header, and the downpipe is tight...that can be a ***** too.

OPAK

it's the cat shield. it just rusts out around the bolts and it rattles. pretty common in hondas

i took that shield off though. thanx for the help. anyone wouldnt happen to know about a sorta slow rattle up near the entrance of my cai into the fender in third gear???

mine does that...its because its a pos

this is prolly a dumb question but what exactly is the purpose of the "shield"??:confused:

its a heat shield...so it doesnt get hot wherever the cat is (cats get very hot)

cats get very hot? well...didn't think they got that hot...thanks for enlightenin' me...:thumbsup:

Yes so hot that in some cars they can bubble the paint above them (again i read that in this forum)

the reason for the heat shield on cats is to prevent ground fires when people park over dry leaves... the cat is hot enough that it'll burst them into flames other wise... the shields absorb and radiate the heat more safely...

there are no "pellets" in a cat... there is a big block of tight honeycombish material which when contacted by excessive amounts of raw fuel will crack... this is MUCH more noticable though and it'll happen ALL the time.. it will sound like a pile of broken rocks in your cat...

the rattling you're talking about could be 1 of a million things... just listen real careful for it; then when the cars stopped go to that area and bang crap around till you hear a similar rattle.

In our 96 ford box truck "pellets" came out of the exhaust, and they replaced the cat. No more pellets