leaky converter flange fixes?

Heyo,

So, I"m currently stumped on an issue on my '94 miata. Trying to get my car ready for oh so wonderful Cali smog after moving here a little while back (been kidna procrastinating) Just went to swap out the exhaust flange gaskets on my car and the flanges are not flat and look to have the rusty imprint of the old exhaust gaskets. I tried eyeballing it and sanding it down to no avail. Looks to be leaking from the bottom of the flange at the area furthest away from the bolts so I think they're out of true.

Any recommendations for fixes? Tried throwing a little RTV red on the gaskets yesterday but I'm pretty sure that also failed this am (buzzing like an exhaust leak..but went away on the drive to work, the flange upstream from the cat looks looks like it's holding, maybe I didn't give it enough time ti cure? ). I'll check when i get back to the car. Maybe duckbuttering a ton of red RTV and skip the gasket? Whatcha think?

If you are using aftermarket composite gaskets, the flanges will warp in at the bolt holes. You can likely beat the ends of the flange back flat, then hit them with a grinder carefully. A flat file will show you the high spots.

If I can't find an oe steel shim style gasket, I will use a wipe of red silicone and nothing before I'll use the composite gaskets.

I've had good luck taking an extra gasket and cutting off the bolt hole ears so it is just the size of the pipe. Use red rtv to make it stick to another gasket so you can line everything up then bolt it up. The extra thickness where it matters is usually enough.

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_x_7020007-P_x_x?cm_mmc=ACQ--Google--GPLA-_-7020007&ci_src=17588969&ci_sku=7020007&ci_gpa=pla&ci_kw=&gclid=CNn4voKEuroCFY6Z4Aod7lIAYw

Might try this...

hah, i'm luckily using a metal style gasket. I think it's just the flange is so trashed from too many NE winters. I might try picking up some files at HF and trying to get it a little more true, then trying to double up on the gasket next. We'll see how bad the leak is when I get under it tonight. Trying to avoid replacing the cat just yet. the matrix in it looks excellent.

Im goofy. I read "leaky converter flange" and thought "you put too long of a bolt in your torque converter and broke it".

I guess i was using Murphy's Law thinking and imagining the worst possible scenario.

Mufler mender past on the mating surfaces. Then heat it uo with a heat gun to cure the stuff. Dont apply it to hot pipes as it will cure almost instantly.

Ford Escorts use an "O" ring style gasket that fits in a groove in the flange. I wonder if others use this type.

Copper Silicone makes for an acceptable gasket replacement on exhaust.