I been searching and have found a ton of 3" in/out cats, not so many 3.5" ones..since my exhaust is 3" I think I just might flange the DP and cat.
I forgot that I need to get it emission tested as it is overdue, but it will give me 2yrs. to figure it out.

 

Def get it sniffed before tearing it apart, which I didnt do to mine lol.

 

Just use 2 v bands, reduce it to 3". After inspection, put another piece back that is 3.5" with no cat.....

 

I don't really know of any high flow cats bigger then 3". If your gonna run it full time, I'd think about splitting the pipe and running two 3" cats. I maybe find a cat off a diesel??? I think that would work... I'll have to look and see how big the one on my dmax is. I think they are like 3.5 or 3.75...

 

Here ya go my friend. We used these all the time at the Chevy dealer I worked at when they would state inspect a diesel they got on a trade in or auction.

Universal MagnaFlow Catalytic Converters


Never heard of any issues with them.

 

Nice, thanks for the link.

 

No problem man! After thinking a bit I figured the best bet is to make two removable sections between the DP and the factory catback flange. make one that steps into a 4" cat then into a 4" catback. make the other section thats 3.5" the whole way into a 4" catback.

just my idea of course

my personal setup with be 3" dp into 3.5" cat/straight into 4" catback.

 

Random Technology also has high flow, big diameter converters

 

I used 2 of THESE. Ultru high flow. Been on for a few years with no issues.

Here is a shot of them installed...



Here is page three of the thread with some other pics....

https://www.performancetrucks.net/fo...-433552/page3/