Ok, I just got a new DC Sports Header installed on my ls. Now there is a slight rattle coming from the catalytic converter and the car also sounds like there is an exhaust leak. Is the car suppose to sound like that with a header? The nuts on the supporting bracket for the secondary pipe broke off, so I just redrilled another hole on it. So now it has only 1 bolt holding it instead of 2. Could that be what's causing the rattle from the catalytic converer? Any opinons will be greatly appreciated. Thanks.

 

the rattle can be from anywhere... probably the cat hitting a heat sheild. did you run the car while it was up on jack stands and listen for the rattle.

As for the exhaust leak, it can be from anything... the donut on the header, like you said, it could also be that the header is held to the cat with one bolt. I used a long grade 10 bold and washer instead of the spring loaded one for one side.

HTH

 

The rattle is not constant. It only occurs when I am starting the car from idle in first gear ( moving the car from a stand still ). Also there are 2 spring loaded bolts connecting the cat with the header. I was refering to the mounting bracket under the engine where only one bolt is holding the header in place.

 

i doubt it. i just stuck the studs through the bracket w/o nuts to secure it and i didn't have any rattles.. did you replace the donut gasket?

 

What's the donut gasket? Am I missing something here? The header came with 2 round gaskets to put between the primary and secondary pipes. I put those in. Is there another gasket that I should be concerned with?

 

OK, it seems like that I was missing the donut gasket. Thanks guys. After putting that on, the exhaust leak is no longer there and the majority of the rattle is gone; however, there still seems to be a slight rattle when I am accelerating at around 1500rpm coming from the cat. I wonder if it's because I only have 1 bolt between the 2nd header pipe and the supporting bracket.

 

hmmm... anyone experiencing the rattle at 1500 rpm with a DC sport header?