Test pipes for my first bolt on!

OhioYJ

If they are non-resonated, there will be no difference in loudness between brands. Resonators will help cut down on noise, and rasp without hurting performance to a noticeable degree.

A cat-back exhaust is by far easier to install for a DIY'er. I did the Berk high flow cats on my 2016 recently, while it 5000 miles on it, the top two bolts on both sides (the ones everyone calls the demon bolts) were the most fun. Everything else was easy. However those two bolts were a bear until you figure out how to get to them and get them broke loose, and then on my car, I still broke the passenger side one. Both my O2 sensors came out no problem, but it's a new car.

It's also worth noting, generally once you get rid of the factory cats, is when you would have the car tuned (when it's recommended). Since you are still running the factory exhaust you're probably ok.

Jayhovah

Ahh yes the "Demon Bolts"... OP search the forum for that term and you will find a lot of information about the pains of removing the factory cats.

My advice:
1) Soak the demon bolts in penetrating oil the day before (at least)
2) Remove the intakes so you can get straight on them with long extensions. You don't want to be messing around with swivels and wobbles.
3) Use 1/2" drive socket/extensions with either a large breaker bar or a powerful air powered impact wrench.
4) Use a 6 point socket. A 12 pointer will just round the thing off faster.
5) Keep bolt extractors on hand... there is a good chance you will start to round one or both of them off. My drivers side was so frozen on I had to put the bolt extractor and two of us were pulling/stabilizing a huge breaker bar and eventually the bolt just broke off to free the cat.

You can find pics of my demon bolts and the tools I used to get them out in my pic dump thread (check sig).

__________________
2013 Gun Metallic Sport - Gamma V3 Twin Turbogized
DIY Gamma V3 TT Install * Jayhovah's Gamma V3 TT Install Pic'Z and Vid'Z * DIY: Washer Reservoir for the Boosted

OhioYJ

X2! I wish I had seen this before I started. I also came to the same conclusion. The only way to get to them is run extensions all the way to the front of the car up near the intake. Ideally with 1/2" extensions to prevent flex, so you aren't fighting yourself with the flex of 3/8 stuff.

My factory catback was out in literally 30 minutes. I spent hours on the cats, because of those bolts. Once those top two bolts were out everything else was easy. Even putting new bolts in for the new cats was easy.