I’m running a catted downpipe on my 2.0 with no tune and didn’t get a CEL, but every car reacts a bit differently. Some people are fine, others get a code eventually. Worst case, yeah—you can swap back to OEM and clear it with an OBD tool.
Tutuapp
For me, swapping to a square tire setup with stickier rubber made a huge difference — way more confidence in corners. Suspension tweaks help too, but tires were the game changer.
Mini Militia App Lock