rattling at 3k - 4k

Originally posted by nonovurbizniz
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