I replaced my fuel tank and fuel module and wanted to replace my exhaust while everything was down.
I purchased the Flowmaster 17233 Catback Exhaust and new hangers.
I now see that the 5.0 E cat has a 2.25" outlet and the FM 17233 comes with a 3" Intermediate pipe from the cat to the muffler.

I would like to use the 3" pipe.
Is there anything that will adapt the pipe to the converter?
Does anyone make a 2.25" cat flange to 3" ID adapter?

I'm also thinking of contacting Flowmaster for the 2.25" cat flange pipe
and using this Summit adapter to connect to the remaining 3" pipes I have...
https://www.summitracing.com/parts/sum-652273/overview/

Any ideas ?

 

You could possibly cut the flanges off the cat and the intermediate pipe. Then weld an adapter to go from the 2-1/4" cat pipe to the 3" intermediate pipe. You could then use a 3" band clamp to attach the intermediate pipe to the adapter so you could still disconnect it for service later if needed. I know clearance is kind of tight, so it may not work, but it's a possibility.

 

I would just weld the factory flange to the small side of the adapter and some new 2 or 3 bolt flanges to the other side and shorten the flowmaster as needed.

Although IIRC the flowmaster necks down enough to bolt to the stock cat or maybe I am thinking about magnaflow.

{EDIT} I just looked it up on summit and after being shocked anyone would pay $500 for that alumnized pile of rubbish I saw this note

Notes: Models with single 3.00 inch flanged catalytic converter.

 

https://www.summitracing.com/parts/flo-17234

Here is the alternate part number with the smaller 2.5" cat connection

 

All you need is the 3" to 2.5" adapter.
Any muffler shop will have it for a few dollars.

I suggest having a shop weld the hole kit together and adding the adapter while there there.