I'm fairly new to renntech.org. I usually use this site to get most of my information on my 2002 996. Well, my car has a K&N intake, rss plenum, and evoms exhaust. When i first installed the K&N, i would get a CEL every-so-often. However, this time it's giving me a P0420 fault code. This was not the same code that was popping up before (i don't think).
I checked under the OBDII section on what this means:
P0420 Catalytic Converter Conversion Too Low (Cylinders 1 - 3)
What does this imply? Is my Catalytic converter bad? Or do i need to change the spark plugs?