High Flow Catted Downpipes with No Tune?

[NoBingusFr]

So far I’ve added MAPerformance catted downpipes, their catback exhaust, and Z1 intakes on my 2025 MT Performance. I know it sounds silly, but in my head I could replace the downpipes with stock parts if needed for warranty purposes. A tune would completely void it. Am I doing more harm than good by not tuning?

The downpipes do have an insert for the OEM o2 sensor.

 

[rocksandblues]

no harm. maybe 2% gain

 

[VR30Z6spd]

if the catted downpipes are not creating any boost creep

sounds good, in terms of gains is these car have closed loop boost control you wont gain much