hi,yesterday when i was tuning for c6 i dnt know whats wrong with this car and this car is already tuned from another tuner so when i reach afr to 13 the car going to 420hp but this is not the real hp because it have long tube headers,lingenfelter air intake with mass air flow, mti stealth two camshaft with double springs, high flow catback and 6psi magnacharger, it should be around 520 to 540 but car is dead and when i tune it to 12afr it reach to 360 hp and everything is ok belt is tight and everthing is looking good, when i am chekin in scanner the timing is around 8 to 10, tune file is attached. thanks