F150 Mod Question

'97 4.6 V8
Put a GenII Intake, and opened up the exhaust with a Gibson cat-back. I have realized modest gains but not quite what I expected. Seems to be several
flat spots in the run up through the gears.
My questions are:
Should I have replaced the cat as well (130k miles on truck)? I did not want to install headers but if a more free-flowing cat is available that's no problem. Will the computer adjust to the increased air flow/exhaust, or can the OEM computer be "re-mapped"? Should I take it in and have a chip installed?
Thanks! Any ideas will be most appreciated.
Jeff
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Jeff Mayner opined in

Guess what!
Change the MAF, Throttle body? Still wont net you much.
You've been caught up in the mod-newby conundrum... just as in the later 5.0's, the factory airflow system is designed to match the heads.
Stock heads are USUALLY designed for fuel economy... eg, the 2.3L heads became MORE restrictive -performance wise- from 86 to 88. Fuel economy went up.
The ONE item that can probably handle more flow is the cats... note I say PROBABLY.
You need to get the hardware that will affect breathing done BEFORE you get a chip.
Since this isnt generally a maintenance forum, you can find out specifics on:
www.ford-trucks.com
and maybe
www.f150world.com
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

went
get a

Thanks.
Jeff
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.