This past weekend, I installed my JDM 4-1 header with Carsound cat onto stock exhaust. Ever since then, my car has been louder and most of the noise is coming from the header. When i'm at low RPM or at normal RPM cruising range, the sounds coming from the header is kinda annoying and sounds like it's leaking...However, when i get on VTEC, it sounds great and pulls hella hard. I'm very impressed with this header. Anyways, do u guys think I have a leak somewhere or is the JDM header supposed to sound like annoying/leaking around the RPM cruising rang?? Any opinion is appreciated...I will retighten all the nutz/bolts this weekend, if it's not cold...

 

There are 2 possible items...

Header --> cat is not tight enough and is not sealing

cat --> b-pipe is missing a gasket and is causing a leak...I'm familiar with this one...

 

this might sound strange, try to feel for a breeze of air where the headers meet the block by using your hands( don't brun your self do it when the car is Ice cold gives you a extra 2 seconds)
and or try tightening everthing while its running and see if you make a diff in the sound...

Just my two pennies, said it would sound strange

 

Yup, I second Austin. My problem originally was the Header Collector (outlet) connection to the Inlet of the Cat. The gasket was alligned correctly, and after 4 different and wasted gaskets I finally bought the correct gasket. Good Luck....gaskets suck! (Umm....that rhymed...=P)

 

Mine sounds the same way, and i have tightened the hell out of ever bolt. I think mine may be the donut gasket, i dont know .

 

Could be that the header exhaust donut/gasket and the joint for the cat don't mate together correctly...
Austin

 

If you checked all your bolts, than what you hear is normal for the header as you can hear a difference from stock.

 

From my experience, it is usually the cat to b-pipe connection that leaks...


Jason