high flow cats without tune?
Thread Starter
Melting Slicks
Joined: Nov 2008
Posts: 2,938
Likes: 65
From: Rochester Hills MI
high flow cats without tune?
my passenger side catalytic converter is rattling, so i need some new cats. if i install high flow cats, is it necessary to have a tune? will i get any codes? thanks!
-Dan
-Dan
Melting Slicks
Joined: Jun 2008
Posts: 2,283
Likes: 16
From: Katy Tx
I recently had high-flows and x-pipe installed (had cam-headers-dyno une before) - definitely needed retune ... had quite a bit of surging on decel - and tuner found a/f to be way off -rich and erratic... new street tune made it all great again.
Thread Starter
Melting Slicks
Joined: Nov 2008
Posts: 2,938
Likes: 65
From: Rochester Hills MI
has anyone done this without having a tune in the first place? i plan on getting a tune next spring, but i dont want to listen to my cats rattle until i finally get it done.
Le Mans Master
Joined: Apr 2005
Posts: 8,077
Likes: 4
From: Scarborough ONTARIO
I did this on my 383 stroker C4 and passed the emmission testing too (sniffer test). Did not observe much differnce in driving or anything.
Now i have LT headers with Hi flow cats, but i do have straight pipes in place of cats too which i change whenever going to drag race or whenever i feel like only takes an hr to switch cats/straight pipes, very little minute difference in LTFT it was rich with no cats, i do my own tuning with EFIlive.
Go ahead and replace em with hi flo cats, but before replacing them u can check urself with infra red temperature gun, before and after cat, and replace with hi flo cats and check again temperature, u should see atleast 40-60 deg temperature before and after cats, rear of cat should read higher, than u can conclude that cats are working and doing its job.
Now i have LT headers with Hi flow cats, but i do have straight pipes in place of cats too which i change whenever going to drag race or whenever i feel like only takes an hr to switch cats/straight pipes, very little minute difference in LTFT it was rich with no cats, i do my own tuning with EFIlive.
Go ahead and replace em with hi flo cats, but before replacing them u can check urself with infra red temperature gun, before and after cat, and replace with hi flo cats and check again temperature, u should see atleast 40-60 deg temperature before and after cats, rear of cat should read higher, than u can conclude that cats are working and doing its job.
Last edited by sami85L98; Oct 11, 2009 at 02:52 PM.
Thread Starter
Melting Slicks
Joined: Nov 2008
Posts: 2,938
Likes: 65
From: Rochester Hills MI
I did this on my 383 stroker C4 and passed the emmission testing too (sniffer test). Did not observe much differnce in driving or anything.
Now i have LT headers with Hi flow cats, but i do have straight pipes in place of cats too which i change whenever going to drag race or whenever i feel like only takes an hr to switch cats/straight pipes, very little minute difference in LTFT it was rich with no cats, i do my own tuning with EFIlive.
Go ahead and replace em with hi flo cats, but before replacing them u can check urself with infra red temperature gun, before and after cat, and replace with hi flo cats and check again temperature, u should see atleast 40-60 deg temperature before and after cats, rear of cat should read higher, than u can conclude that cats are working and doing its job.
Now i have LT headers with Hi flow cats, but i do have straight pipes in place of cats too which i change whenever going to drag race or whenever i feel like only takes an hr to switch cats/straight pipes, very little minute difference in LTFT it was rich with no cats, i do my own tuning with EFIlive.
Go ahead and replace em with hi flo cats, but before replacing them u can check urself with infra red temperature gun, before and after cat, and replace with hi flo cats and check again temperature, u should see atleast 40-60 deg temperature before and after cats, rear of cat should read higher, than u can conclude that cats are working and doing its job.
Le Mans Master
Joined: Apr 2005
Posts: 8,077
Likes: 4
From: Scarborough ONTARIO
Which hi flow u getting, metal mesh or ceramic substrate, i doubt on the codes will pop up, but might be, even if comes it will be rear cat efficiency code that will not effect performance though, u can even disable code while driving on DIC, it will come back disable again, till u get other mods and do tune at the same.
