Shouldnt be. You can take a look at the engine compartment and look at the nuts and bolts wheter they have been opened before. As for the injectors and the fuel system all is standard. If i remembered correctly the injecors are running close to max.
Here is the thing. For my rig parts that i ave changed for increase peformance. Drop in replacement k&n filter, cam gears in/out, 3" exhaust system, power Fc and that was it. I got 236kw @all wheels. I was running mobil fuel when tuned. Everything else is standard, fuel system, engine, boost controller, clutch.