cat question

[CountryBoy704]

i've got stock exhaust probably putting on a used flow 40 soon just wondering does putting a high flow cat on really do much? and would i need to stack 2 of em like the oem cats come to keep it legal?

 

[kcm1582]

Simply put no. The factory cats have very little restrictions and a high flow cat won't really change that. as far as stacking them I'm not sure but I believe the keep the truck compliant with federal regulations you would need both.

 

[7.5L_STX]

i think you only really need 1. dont quote me though

 

[Sasquatch_Ryda]

You would only need to use one as they are a universal cat that has both catalysts in one unit. Ford decided to put a different catalyst in each unit on the stock set up.

If they aren't plugged or falling apart there will be no gains from swapping a 'hi flow' unit in its place....other than lightening your wallet a bit.

 

[kcm1582]

You would only need to use one as they are a universal cat that has both catalysts in one unit. Ford decided to put a different catalyst in each unit on the stock set up.

Interesting, I learn something new everyday.

 

[adsm08]

i think you only really need 1. dont quote me though

oops.


Nah, Sasquatch is right. Ford put the different catalysts in different beds of the converter. The universal, high flow, w/e ones have them all in one bed. As long as you get the three way catalyst you will be ok, not that the high-flow will help any.