Are they as queit as the manifolds are there much louder I wanna put headers but I don't want the noise thats why I never bought none I like the car being queit .

 

Catted headers will still be louder than stock manifolds, definitely. The biggest factor will be what catback you have though. You can always try catted headers w/ stock catback or a hooker catback. That should be quiet enough.

 

A local CTS-V owner wanted more power but refused to go to headers on that car, as he wanted a nice DD, and not a hot-rod (i.e. didn't want to put up with burnt wires, gasket leaks, etc.) Regardless of his motives, he had his stock manifolds extrude honed, and gained about 10 rwhp, eh then coupled that with a nice set of Random Tech high flow cats, and gained about another 10. OEM quality, with none of the header issues. He only gained about half what he would have from headers, and spent about the same price-wise.

I have kooks headers + highflow cats + corsa cat back on my car, and at WOT is is hella loud. At low RPM, I set off car alarms in the parking garage at work.

Food for thought.

-Chris

 

Check the external engine section, should be some examples there