Was about to order the magnaflow Y-pipe and was thinking about replacing the cats with some magnaflow hi-flow ones. I already have a cat-back exhaust but wanted to do something about the exhaust that runs from the collectors to where the new Y-pipe is gonna go? All opinions are welcome....

 

41 views and no opinions???

 

I would stay with your stockers unless they need to be replaced.

 

how do you know when they need to be replaced? I just have a hard time believing that the stock cats flow as good as some magnaflow hi-flows....

 

They don't but they are a high flow cat, the Hemi engine design is all about breathing and the 3rd Gens got some pretty high-flow cats as a result. The Maggies will flow better, but not enough to tell unless you ran a dyno and even then we aren't talking much.

I still have my stockers WITH long tube headers. There is just not enough gain to be made here to justify the cost until the stockers fail.

You'll know, that's what the post cat O2 sensors are for...

This is another one of those things that USED to be true but isn't anymore just like getting a benefit from a Throttle Body spacer. Was a day when it did some good, but that day is past. Was a day when cats killed flow and performance, but that day was back when your dad had cats in that 1980s Buick...

 

Well the main reason i want to change all that stuff out is that i'm getting this really annoying ticking sound from that part of my exhaust(right after the collectors)and it starts like 10 seconds after i start it up and it's pissin me off,i hate when my truck makes a noise that it shouldn't.I figured if i was gonna do the y-pipe i would put all new cats and get ride of all the older pipe from the collector back.It's not really a performance thing but that noise has to go.