Tuning out in what circumstances?

[et5828]

In what condition do we need to retune our piggy back system?
1)change exhaust?
2)change spark plug?
3)change engine oil viscosity?

i was thinkin to get one of these piggy back like safc or e-manage, but do they run out of tune if we do the following things?
kindly share some knowledge pls...

 

[et5828]

anyone? no one wanna share info's here

 

[kelisa6009]

et

if u change exhaust then u need to tune your setting..but the rest i think should be ok....