Installed Megan 4-2-1 headers, Magnaflow cat, and Tanabe Medallion Touring cat back. Sounds great. But my midway flange gasket blew on my header the other day. I used some blue silicone rtv sealant that i found in my garage. guess it wasn't good enough. the midway flange separated and the car was sounding like a v8 lol. i guess the header got real hot b/c now my stainless steel header is yellowish lol. i saw trustdestruction's thread about the gasket so i'm going to buy some metal gasket material from autozone and copper rtv sealant. took some pix today:

 

nice.
yea follow the instructions on my thread and your problem should hopefully go away.

make sure to use sandpaper to sand off the old gasket remnants from the flange, and that the flange is smooth and clean before installing the new gasket.

 

yea definitely. don't want that happening again.

 

I have megan racings 4-2-1 header and it has turned a off yellow color. My question is without to take apart my header mid flange connection, how do I know if I have blown my gasket or not.

 

jack up the front end just a little, and then with the engine running, carefully reach under the bumper and put your hand around the flange (not touching the header) and if you feel any air coming out of the flange, your gasket is blown. (don't be fooled by your radiator fan blowing air though, only do this when the radiator fan is off, to reduce confusion.)

 

ok re-installed it earlier. it took me a while to find the gasket material. someone at arch auto parts told me about a speed shop around my way and i got it there. the autozone i went to was out of the sealant in the tube so i bought the spray one and i put on a few coats. i'll run the car in the morning and hope the gasket lasts this time lol.

 

thats weird, i remember a different thread with somebody who has a Megan 2-piece header and kept blowing that same gasket as you. Must be a common problem. This might help (from the Header FAQ):


Note for installation of a two piece header, this is referring to the gasket between the two pieces of the header: Torque the middle bolt first to 15 ft. lbs. Then the remaining to 15 as well. Then after throttling the engine a few times to break the gasket in, torque all bolts down to 25 ft. lbs.

Might make a better seal.

 

That was probably me and Live_4it

Live_4it said he did that with it and it still had problems

 

well its been a couple days. so far so good. man i love this setup. not loud at all. sounds close to stock. the exhaust was pretty expensive but worth it. only thing is the exhaust tip sits right on the bumper so it vibrates on it sometimes. ill fix that soon.can definitely feel the difference after installing the exhaust and header. still not where i want to be tho. hopefully next spring i can do a swap. or if i can find someone selling a supercharger for my engine :-)