What gasket should I be using for the connection of the O2 housing to the downpipe? I've got a IX MR and I recently crushed the bottom of my Megan downpipe, which had the older style flex section in it. I ordered a replacement Megan downpipe(ACD version) to replace it, but it only had one flat gasket in the box, so I reused the donut gasket on the O2 housing that was used for my old downpipe, and put the flat gasket down where the downpipe bolted to the test pipe. At this point it runs perfectly fine with no apparent exhaust leaks, but I am wondering if I was supposed to use that flat gasket at the O2 housing, because the donut gasket didn't fit the new downpipe nearly as well when I bolted it up, and the new downpipe won't clear either of the lower tie bars without using longer bolts and washers to space the tie rods down lower. Any help clearing this up will be greatly appreciated.

 

Anyone...anyone? Beuhler?

 

the donut gasket goes on the o2 housing where it connects to the dp... its a little hard to get on there but thats where it goes... the flat gasket goes where you have it between the test pipe and dp

 

Reuse the stock gasket thats on your o2 housing.

 

Perfect. Thanks everyone for confirming that I'm not an idiot. I'll go get some longer bolts and washers tomorrow so that I can bolt my lower tie bars back up.

 

lower tie bars are over rated.

 

I'm not sure if that's the case with aftermarket lower tie bars, but I must say that it was pretty easy for me to get the OEM tie bars to flex.