Rattling Cat???

[w.neurauter]

Hi Everyone,

I have a 2003 gt with a stock h pipe and I think one of the Catalytic converters is rattling. There is just a small rattle around 2,000 rpm that only occurs when the car is warmed up. I got underneath it and banged on the cats a bit to see if I could isolate it to one of them but couldn't tell if any of them were rattling. I did make sure to check the shields to make sure that it wasn't one of them.

Does anyone have any other ideas, or other things I should try to pinpoint what it is? It seemed to get better for a week or so after I was banging on them but came back this past week.

Thanks for the help

 

[myponyrocks]

one of the shields may be loose, they are only tack welded on. Some JB weld will fic your issue. If its one of the ones higher up, just replace the midpipe, you'll be happier with 2 or 0 cats than with 6.

 

[jstreet0204]

My BBK hpipe had a chunk of the cat material break loose and would rattle around inside there like you are describing. take it off and see if you can dump it out.

 

[Matt's 03 GT]

Does the 2003 Have 6 cat's also... I assumed that was only the NPI GT's...

If so, I don't have a stock mid pipe...

 

[w.neurauter]

Thanks for the replies. I am 99% sure my cat is stock and it only has 4 cats.

I have thought about taking it off to see if I can get anything to fall out but since it only does it when it is warmed up I figure that taking it off while it's cold won't do much good.

Does it make sense that it would be a cat since it only does it when warm?

 

[jstreet0204]

Thanks for the replies. I am 99% sure my cat is stock and it only has 4 cats.

I have thought about taking it off to see if I can get anything to fall out but since it only does it when it is warmed up I figure that taking it off while it's cold won't do much good.

Does it make sense that it would be a cat since it only does it when warm?

Mine did it warm or cold but only at certain rpm.