Problem with Cat converter and low idling. help!

[Mazdspeed]

So i bought an after market Catalytic converter about 6 months ago then installed it, Now it is making rattling noises when i start my engine. I took it to the mechanic and he told me I need a new cat converter because the one i have now broke ( or something got loss inside the converter ). I contacted the seller [whose company is in Canada] and he wants me to send the part to Canada so he can take it look at it. my car have been idling low for the past year and i was thinking maybe that's what made the cat converter break. when my car is at stop the RPM hits 400 and if feels like the engine is about to shut off.

is there any way to set the RPM higher ?

and should i get that fix before i buy another cat converter ?

thanks for you comments in advance.

 

[StealthWyvern]

Do you have any vac leaks, have your shop test your IAC(Idle Air Control) valve

 

[Mazdspeed]

I havent yet checked that. ill do it this afternoon. ill keep you updated. thanks

 

[squire0311]

wrong sectoin but a cat on a turbo car isnt good for the turbo.

 

[nate0123]

wrong sectoin

fixed

 

[Mazdspeed]

I checked the car and there is not vac leaks and aic looks good. any other suggestions ?

 

[squire0311]

Run catless if you can. I'm running on custom 2.5 inch with a resignator only and an apexi can. Sounds like a mixture of an evo and wrx.