....It's an aftermarket intake, not a exhaust, which can upset the fuelling. If you have Revo you can adjust the settings to compensate and avoid the added expense a fuel pump until/if you decide to go to Stage2+ (Revo).
He has a giac remap and not revo therfore doesnt have the chance to run reduced settings to compensate for the intake/exhaust.
Correct me if im wrong but i was under the impression that the addition of the exhaust freed things up so the engine could process more air which in turn will mean more fuel, obviously the intake will allow even more air in to the engine but i thought he exhaust will also cause a slight alteration in fueling, well not alteration.....you know what i mean though
Also mate, another think to watch out for when buying an exhaust on a giac mapped car is make sure you specify 200 cell cats as the giac software doesnt disable the check light, and running 100 cell cats could cause the fault light to illuminate.
Im assured it wont come on with 200 cell cats