Well I have had my CNT HFC's for about 1k miles now so I thought I would do a real quick review since I haven't seen a whole lot about them on here. I am running these with a stock exhaust and my only other mod is R2C intakes. First off, sound - when I first got them on they sounded absolutely terrible. The rasp was so bad and it sounded like a honda fart can. BUT I will say that as the miles added up on them they have gotten much less raspy. The strangest thing about them now is that when the engine/exhaust is cold, they are still extremely raspy, but now as soon as the car warms up after about 5 mins of driving they get much smoother and sound a lot better. I'm very surprised at how loud this car has gotten with just the HFC's. Most people say that HFC's make a marginal sound difference but I will tell you with these the car is very loud. I've had many of my co workers tell me they can hear me leaving from inside the building. Now as far as power goes, again when I first got them on I felt like it lost some power and considered taking them off, but after resetting the ECU and putting some miles on them it feels better. I could never get the car to chirp 3rd gear before these but now I can occasionally get a 3rd gear chirp, so it must have gained a little power. Any questions you guys have about them just let me know!

 

Got any pics of them installed? How did you go about resetting the ECU? No codes?

 

Don't have any pics. I just disconnected the battery after the install. No codes at all and i've had them for a few months now.