2G gst exhaust flanges wrong size?

[shifty2006]

I have had an exhaust sitting around for a year or two just been too busy to undertake putting it on. My issue is that it's a megan dp it starts 2.5 then goes to a 3" but the cat back portion goes from 2.5"-3" so where the dp and cat back mount up has 2 separate size flanges I'm not sure I can just bolt these together and it stay sealed..?

 

[Talyn]

Are you sure it doesn't eliminate the cat from the exhaust system?
This product description says it eliminates the cat:
http://www.extremepsi.com/store/product.php?productid=20724&cat=0&page=1

 

[Silver gryffon]

Some cat backs are made to fit the original cat. That would explain the issue, if it's not a cat delete.

 

[shifty2006]

So I took another look at it finally and yes the system eliminates the cat but the issue Im having is the dp ends on a 3" and the rest of the exhaust starts on a 2.5" both with flat flanges so im asking how do I get the two to seal together do I just slap a 2.5" gasket in there and call it a day or is it going to leak like crazy?

 

[Silver gryffon]

I'd say your downpipe is a cat delete, but the rest isn't. Safest way would be to get a different downpipe or replace the front section if the exhaust. It's best if they are the same size.

 

[shifty2006]

Yeah just took it to the shop and had them cut the flange and weld a 3 inch paid more then I would have liked but it's on and done.. thanks for the help.