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H6 Factory Exhaust Diameter?

16833 Views 13 Replies 5 Participants Last post by  CNY_Dave
Hello everyone. Ive been doing some searching but can not find the answer. My Mom's 01 outback H6 exhaust has a rust hole in the exhaust near where the midpipe meets the axleback. I need to get some supplies to fix it.

Does anyone know what the factory exhaust pipe diameter is?

Thanks in advance!
1 - 6 of 14 Posts
It is double-wall pipe, that's why it necks down for that joint.

That joint 'wore out' on mine, I ground down the flanges (what was left of them) and used a short piece of 2-inch pipe over the whole joint.

I had to grind down the weld on the inside of the pipe, 2.25 inch pipe would be a lot easier, but you'd have to really crank down on the clamps.

2.25-inch flex pipe might be the best easy choice.
The factory pipe is 2-inch outside-diameter. Flex pipe is avail in different sizes.

Flex-pipe doesn't last long, though.
Crap, it's not 2, it's almost 2.5.

2.5 inside-diameter pipe would be easiest.
The cheap stuff, due to rust, so stainless should work.
Slightly oversize on tjhe pipe will hide a multitude of sins (bends).
Yes, just clamp the heck out of the bugger. 2.5 might be a lot of squishing for a clamp.
If I need to I can heat the pipe with my acetylene torch and squish it any arbitrary amount. A good propane torch or MAPP torch might do it.

Cheap pipe you can clamp down quite far, good stuff from NAPA not so much.

You need to use the heavy-duty clamps that have the little buttress where the nut pushes.

If you can orient the pipe clamp so it follows the 'fat part of the curve' you don't need to crank it quite so far. The exhaust sealant stuff could be applied where the clamp is going to go to help insure a good seal, but a small leak there isn't a big deal to my mind as long as it doesn't blow on the diff, u-joint, or CV joint.


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