I want to do some long tube headers on my denali. Im tyring to do it as efficiently and cheaply as possible. Here is what i have: Flowmaster 50 series DI/DO muffler. Factory exhaust system including two cats. If i ran the headers could i put one factory cat after each header then into my di do muffler? that way i wouldnt need a y pipe and could use all my same stuff. If not how much would a high flow cat cost to run after a y pipe. If i do that i will do a cut out and want a fairly quiet muffler that is also cheaper. What are my options on that? Thanks.

 

maybe this thread will help...

https://www.performancetrucks.net/fo...d.php?t=377663

 

so do you have to have either a x pipe or y pipe? I mean would two cats and a muffler not be sufficient back pressure?

 

anyone? Are my factory cats restrictive? Are they sufficient?

 

These are VERY basic questions that could be answered in just a couple minutes of research.
If you run True duals you don't need X pipe, X-Pipe helps make the flow more efficient between each side of the engine.

You can run LT's and have the Same setup you have now, just buy the headers and go to a muffler shop and have them weld the cats on and run the pipe.


Search is your friend.