i think i have a cat conv problem


10 Year Member
Mar 31, 2005
Atlanta, GA
hey guys, i havent been around in a few days. ive been out of state on vacation and what not.

Anyway the past day since ive been home my car has developed a strange noise and i am pretty sure its something coming loose in one of my cats but i am not sure so i made a video:

there is no check engine light on my dash and the car doesnt seem to have any throttle response issues however i havent gotten on it really since i am not too sure whats going on yet. however when i accelerate from a stop i can hear that my exhaust doesnt sound right. at times it sounds like a hemi :eek: when i let out the clutch to decelerate the exhaust system underneath my car sounds like it is rattling out. the rattling you hear in the video is mild to what it sounds like when its under a load.
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definetly sounds like a cat. to me. Throw it up on some jacks, wait for it to cool, and give a light to moderate tap with your palm to each one of the converters. You should be able to find out which one if any are breaking up or loose. I recently replaced one of my cats on this magnaflow X.
cat problem

um yea your cats definitly bad do like i did little pricey but blows the rest out of the water (bbk,mac) get a basani o/r xpipe w/ cats and if you dont live in a polution controlled state like cali. have a shop remove the cats and get mil elims. for the check eng. light and enjoy that hellashish noise youll enjoy making for years on end:
well in my state i need the cats for inspection so an o/r pipe isnt a choice

if it is a clogged cat that needs to be replaced i will probably buy a full slp mid pipe so i can replace the cats without having to deal with this again

if i do get an slp mid pipe i could always get the race pipes that go along with it.

its only been on the car for about 2 years now. would i not get anywhere by calling up BBK? 2 years seems pretty short dont you think?
Do you have a CEL? You mentioned BBk so I'm assuming you have a midpipe on already...are you already using MILs? If you dont have MIL's on the car, a cat that sounds like that should set a code. Atleast thats what common sense tells me.

I had a bassani catted x on my car for a long time and it developed a sound exactly like that that just got worse and worse. I figured it was the cat breaking up as well (no MIL's on the car, had a CEL), and I wanted the o/r sound anyway, so I got a mac o/r h and swapped it out. When I got the bassani x on the ground, I noticed it was actually just the heat shield around the cat, and the cat itself was fine. Just the way it was broken and how close the midpipe was to the body of the car, I didnt even notice. Check your heat shields.
How much are replacement cats anyway? I have a catted h pipe that seems to have a slight rattle on the left cat. It doesn't sound too good at 2100-3000 rpms, but after that it goes back to "normal".

:lol: um replacement cats arent that bad unless its the very front ones then you can delete that one as long as you have one between the first and last o2s sometimes it wont hurt anything but if it was like mine and had six cats that sucks if you got to have all six in your state but in north carolina you only need one per side and it only has to appear that its there it dont have to functional but i think loudmouth by slp sounds awful, id leave slp for gm and go basani or steeda stuff, bbk and mac are alright bu dont last aslong