why not just leave the cats off and fudge the smog?

 

where did you have them mounted at? When my exhaust guy saw my stainlessworks y-pipe he told me I should not have the cats mounted right after the LT collector or they were sure to burn up. On my new set-up both cats were placed after the trans x-member.

 

those sure do look metallic to me . It seems like the ceramic would just break up???

 

I did a search on that part number and they are in fact a metallic substrate. The 54959 are also rated for the same displacement but with a ceramic substrate. I chose these specifically because of my experience with the stainlessworks metallic substrate material.

 

i was referenced the jegs website....just looked at the magnaflow site. i stand corrected. i had metallics. looks like its time to try ceramic. only thing i do not like is that they are only rated for ~5 liters. i am 6.1 and blown....hmmmm

 

they were mounted at the header collectors

 

I am kinda confused. I did some research and I also have the 59959 and bought them from jegs and i have a ceramic substrate and are rated for 6.2l at 6000lbs. Jegs says ceramic and online says "revolutionary metalic substrate". I wonder if they changed the design of this model. I know I chose the 6.2 rating for my blown application and they are in fact ceramic as I checked before the install. Hmmm.

 

Actually you want a cat converter as far forward as possible if you want it to work properly, it needs to heat up. I have been running the SW's and catted y-pipe for a few years now with no problems, but my setup is mild and I'm not boosted. Seems like these cats don't like boosted applications.

 

if you get caught the VIN is branded a gross polluter and there are big fines. its not worth it.

 

i am going to call magnaflow tomorrow. there is a definite discrepancy between the magnaflow and jegs websites.