OK first question how many pounds should I put on the screws that go to the header??

Second question I just put on a megan racing header and I still have the stock exhaust.. Now my car howls and vibrates when I hit 3000RPM and when I down **** does anyone know WHY???

Please help its driving me crazy!!

 

Just tighten them up as much as you can with a 3/8" wrench.... As far as the ratteling, thats easy to answer. The megan header is slightly longer then the OEM one. THat means its pushing your OEM exhaust out of alignment and its hitting either your under body, or USS (if you have one). THere is a very simple fix. Have a welding shop cut 3 or 4 inches out of the stock exhaust and weld it back up.

 

I really tighten the header up as much as I can I thought that i could crack the head that way isent it aluminum?

 

Don't worry about it.... As long as you got em nice and tight, they arent going anywhere....