So on my 04 Fx4 I have 4 catalytic converters and as of now I have true dual cherrybomb extremes dumped under the bed, im looking to make her a little louder at idle an pop a little more at wot; my question is if I take off two of the cats will my truck throw a code? And if not, which two can I take off? Thanks for the help guys!

 

The 2 back cats... Leave the fronts alone.... Just cut the pipe after the second 02 sensor. No codes with this setup.

 

I plan on doing this soon. What diameter of pipe did you weld in?

 

Looks like 2.5"

 

Keep those rear cats....they will need to be re-installed when you sell the truck. It's illegal to remove any emissions equipment that came from the factory, unless it's replaced with an oem type replacement part. Federal law, not local. Hefty fine if you sell it with them removed.