So far the only other performance mods I have are my ARK cutback and R2C intakes. I'm planning to finally get BERK HFCs done in the next month. I'm just wondering if I'll need a tune or if I can run without one once I add the BERK HFCs.

 

It is my understanding that there will be some leanness, just don't know how bad it is going to be. I am going with "if exhaust smell like gas while it idles" a tune we will be getting.

I am about to do the ARK+Berks myself within the month. Anyway, I think a tune would be a good thing regardless.

 

Why do you think it will run lean?
The A/F (air/fuel) sensor will detect any lean or rich condition and adjust the air/fuel mixture (via the short & long term fuel trims) to meet the designed target.

Don't worry and have fun modding the car.

 

It's not going to run worse, if that your worry. And the car will likely have more power than otherwise. Enjoy the mods, and get it tuned someday, but not as a requirement brought on by high-flow cats. Do it on your own time as a modification in its own right.