My mechanic's thoughts on the Berk CBE & HFC

Shadax

So I just dropped my car off with my mechanic with whom I've given business for many years. Very professional, very honest guy.

Now, I'm trying to learn as much as I can about my car and at the same time could not hesitate on getting the exhaust done. I wanted some power gain and definitely a nice sound.

I dropped my car off with him along with the Berk Tech CBE exhaust and HF cats. He immediately started to shake his head and attempt to convince me that there won't be much flow over the stock cats. "You'll be back in less than 2 years with a CEL. So don't say I told you so." He even excluded the cats from the work order documentation and said "We'll just say these were already installed if anyone asks, these are likely illegal and you probably got scammed."

He also mentioned the platinum on a factory cat vs. a lower grade metal on aftermarket parts. He's obviously favorable to leaving a car stock.

We put the car up on the left, and he began mentioning that the car has 4 cats...? He was pointing at the piece between the cat and the header -- isn't that still part of the factory cat?

I'm still having him install it after my rebuttal of "Well, I read lots of great reviews about this setup on the community I visit and seen countless videos of the setup with praise."

Did I miss any steps in my research? Are these HFCs not worth it (or scam)?

It was very difficult to argue with a mechanic when I know little about cars in comparison, but I have been so excited about the install I didn't want to box them back up and ship them back.

When I pick my car back up in a few hours, is there anything I can tell him to have as an argument on why it was a good idea? (aside from the obvious fact aftermarket parts are a huge frown on anyone that prefers factory parts and isn't exactly into modifying a $30,000 car under warranty -- I just couldn't deal with how quiet my car is. But now I'm feeling like I'm adding a sweatshop re purposed piece of metal that belongs mickey mouse'd on a beater)

All thoughts and advice are greatly appreciated