Hello,

Does adding an exhaust and intake before break-in period affect the engine negatively? Is it safe to do or just wait till 1200 miles?

 

I would say just do the break-in before you do any mods. Not just to let to engine properly break in but to catch any forseeable problems without having to worry if it was the car or teh aftermarket pieces you put. The dealer will try to blame everything on your upgrades. The break in period is a good time to fish out any problems your car may have, stock, and get then fixed (under warranty). I thought 3000 miles was a proper breakin...