Further to this, the MAP values are used in the 'L' tables.. Tuneboy ( & Tune ECU) have F & L fuelling tables. F is used on throttle & L for low throttle & off throttle fuelling. You can set the % throttle opening where these tables crossover.
Mostly L tables would be adjusted to eliminate popping on overrun after fitting more open pipes.
The lines themselves shouldn't be problematical, just make sure they're not twisted up or loosely connected.