these are the 3" in/out cat i got today, was bored so i went looking thru magna book and found em paid 150 bucks there brand new so i got em! normal is like 210 or so.. next week or two ill be getting longtubes and custom y... didnt want a bad fuel smell and was hoping these would tame the loudness little better than straight y pipe (what yall think?).. i think they will look nice under there once installed.. also have airaid intake that ill be here tomarrow..



also jw but do you have to take heads off to change lifters on ls motors?

 

ya u do.

 

Fml!!

 

Myself and several others have melted those cats in F/I applications..From what I understand they are very sensitive to rich fuel conditions and that multiplys with boost....

With all that said I run those on my truck...but I am N/A and run a WB sensor,just thought I would give you a heads up

 

well wont have to worry bout the boosted part at all anytime soon! but im just doing full bolt ons on my truck i wanted to do a different cam but i change lifters with different cams, i have never installed a new cam with old lifters, was going to do ls7 lifters anyway but not anymore! i wont be taking the head off of my 09 anytime soon way to new to be doing that just yet haha.. and yes when i get them put on they will only have maybe 100 miles of being on an untuned motor.. so if they wont hold up to that then im in trouble anyway! but ya im going to be ordering a aem digital wideband and tranny temp guage.. thanks a bunch tho this site is great for feedback on all kinds of stuff

 

pretty much the exact same cats im running....taking them back off this week to see how they've held up. I never really wanted them on there anyway.

 

ya man let me kno how they did.. i really dont wana run without cats unless i have to! but i guess if something happened i work at a auto parts store so haha WARRANTY!!!

 

a local exhaust shop once told me there is really no difference in a "high flow" cat than regular cats. They just don't brand the name of high flow to the stock cats. Pretty reputable shop. I'm not biased but I'd actually like to see a test done with stock cats on lets say an exhaust set up with headers and after market muffler and the same set up with aftermarket cats. Even if its close I cant justify replacing them for that price. I"d rather take 150 bucks or more and spend it on something else.

 

well i would use factory cats but on my truck im keeping it to were i can put EVERYTHING back to stock so if i ever sell it and buy another truck thats the same i can put it all on there or do some selling to get new parts.. otherwise ya, im not saying these are high flow but they would be more than the stock cat.. so i can go from to grampa style driving in case he buys it !!! haha

but i reall dont kno about the power out put on different cats, but i do believe one can flow more than another depending on construction of the cat.. kinda makes you wonder tho are "high flow" worth the extra $, i see what you mean for sure! but real reason for me is fuel smell and hoping these will tame the loudness some as well