Exhaust "rattle" After Pipe Replacement Options

[Mystique64]

I have had a "rattle" on low rpms and when the car first accelerates ever since I had the pipe replaced from the header to the cat.

It seems the rattle is actually inside the catalytic converter after I tried to find it by tapping on things. Is it possible something in there broke loose once it got the increased pressure ?
The old pipe was corroded and letting out alot of the exhaust gasses before. Just wondered if anyone has experienced this too.

Misty

[Az3g]

you could always unbolt it and look inside.

[Mystique64]

you could always unbolt it and look inside.

If I did unbolt it it's just gone from the system. We don't have emission inspections in my state. I'd then do the "illegal" mods needed to keep the before and after sensors from reporting problems.

[SRSONE]

the new exhaust probably didnt have anything to do with it...

the cat inside probably broke apart...so u will probably be getting a check engine light anytime now for cat efficiency
u either can replace it with a stock one (very expensive)
or replace it with a good aftermarket high flow one...

[Az3g]

Ya, if emissions aren't a problem id just strait pipe it. that's the cheapest way. And i dont know if you saw what i posted in another thread about o2 simulators? but that's what you will need to avoid the check engine light.

[Boost_Junky]

The header might not be tightened all the way. It could be another engine part. It could be in the cat itself. But most likely its the exhaust hitting a part of the car when you accelerate.

Try to see if you can link the rattle to certain driving input. Chances are small on the cat, it didn't magically happen because of your larger headers. Back pressure change is not all that much. It would be highly unlikely. I mean, it could happen, but it doesn't often.

[bobthecow]

Exhaust hanger

[Mystique64]

Thanks so much for all of your replies. It does seem to actually be inside the cat. I have checked all the hangers etc using a neighbors ramps even after taking it back to Midas and having them check it and bring me into the garage while it was up on the lift. So far no check engine light .. Once it warms up the rattle goes away so I'm not going to worry about it at this time.