hey guys,

i have a 94 ex with a megan 4-2-1 header, a magniflow high flo cat and a full aluminized flowmaster 50 exhaust all the way back.

i have had an ongoing exhaust leak well since about 2 weeks after i got my megan header and i know these are prone to leak so i have changed the gasket by cutting out a template from a sheet of material.

the only other places i can think of that the leak is coming from in the head seal or the donut gasket on the flange to the cat.... i just replaced the head exhaust gasket around 6 months ago and the donut gasket seems to be the culprit.

have any of you guys shared the same problem? someone mentioned a heat shield rattling but i just retightened those bolts as i just did the rear disc swap on my car, so before i get it back out there, any suggestions on how to keep it from springing a leak in the future?

i guess i can get a new header but that doesnt seem to make much sense and the exhaust does not have any holes in it, it was just welded up about 6 months ago and is still pretty much brand new so its from the donut-flange gasket forward.

thanks!
James

 

The Megan Racing header's midway flange gasket probably blew again. Next time, remove the lower half of the header completely, clean off both sides of the flange, cover your new gasket in Copper RTV, and then attach the lower half of the header to the midway flange. Torque those bolts down. Then attach it to the catalytic converter. Drive the car and then park it and let it cool down. Re-torque the midway flange bolts again. Then check it again the next couple days to make sure the bolts stay tight.

 

yeah, i have done like four times now :-D

i actually followed your thread on how to do that but me and my buddy stuck our faces down there and it seems like its coming from the donut gasket...

when i got my new exhaust, the guy took my stock flange and welded the cat onto that so do you think i have the wrong size donut that came with the megan header? that's what sparked this is i totally coated the thing in the copper sealant and did what you said to do...it's kinda been an ongoing problem for a while...

thanks for the help, can i just go to autozone or do i have to go to honda for that part?
James

 

autozone should have the donut gasket

 

ok, thanks i will pop that off and check it out here in a bit but my dad suggested that i double the midway gasket, do you that would help or hurt?

also what's up with the megan headers? lol

 

I wouldn't double the gasket.

The Megan Racing headers are great besides that one problem. Once you take care of the gasket by taking extra care to get it sealed good and snug, the header is pretty good.

 

yeah thanks again, i didnt double seal the gasket, i left it alone but the wonderful people at napa hooked me up with a double sided donut gasket and smashed it in the flange with the spring bolts, because i think this is where the problem is..

that damn midway gasket better hold this time! i sealed all around it too just as a precautionary, heat cycled it 2 times and then re-tightened the bolts so i'm hoping it holds...

only place left is exhaust head gasket,

 

I would recommend getting your car up in the air when it's cold, and then let it run while you check for leaks. That should tell you exactly where the leak is coming from. I've noticed that it's sometimes really tricky to completely eliminate all leaks, especially donut gasket leaks.

 

haha yeah i have come to notice that by now, it's up on jack stands right now, i will start it up and leave it there once i get my brake booster back in there and with all hopes its sealed up, it sounds great, i love the flowmaster exhaust but the tick tick tick sound is annoying!

thanks again for the help!