The engine runs great. And there is no code. I was thinking about buying a non fouler but so far so good. I was super surprised at how good the exhaust sounds now. It is the perfect balance of sound between the air intake and the exhaust rumble. Zero raspiness. All deep growl. Throttle response is much better now that my muffler isn't clogged up and I have a test pipe. And it only cost me 26 bucks for the test pipe off eBay.
When i first got my F23 accord coupe, I cut off the muffler for the fun of it and added a CAI and it sounded pretty good for what it was. I added a test pipe and instantly regretted cutting off the muffler first.