I currently have a JDM chip, small upper pulley, JBA headers, and shift kit. I just wanted to know how much improvement is there with an aftermarket air filter over the stock set up (including stock paper fitler). How much improvements have you guys seen? I also wanted to remove my cats, but had a question about the post cat O2 sensors. Do i need the plug that tricks the computer for this mod, or not? Where do i get them if i do?

 

Not sure about the difference w/ the 2001 air intake, but I'm sure you would see a difference with a ram air setup, like Johnny Lightnings.

You can have a chip tuner turn off your check engine light for !cat.

I used to use MIL eliminators on my 98 Cobra, but I don't know if they work on the Lightning. I believe it was Dallas Mustang who sold them.

 

If you remove the large cats you won't need anything to trick the O2's, they won't set the engine light. You WILL lose performance.