ruggerisa

I have 02 camaro ss m6 with QTP long tube headers and y pipe with electric cutout. LS6 intake with SLP cold air kit (came stock on the car), TSP 228r cam, 112 lsa, PAC 1518 springs, 7.400 pushrod length. Pro 5.0 shifter,Motive Performance 3.90 gear. I had the car tuned before I installed the cam and was told i didnt need retuned just needed the idle touched up. I never got the car retuned because the idle was fine and it drove fine for about a month. Now i know with the cam that the p0300 (engine misfire detected) is a common code that comes up and can be fixed with a tune. Now I am clueless how to fix the other codes, the p0101 (mass air flow sensor circut, range or performance problem), p0106 (manifold absolute pressure sensor circuit, range or performance problem) and the pending code of p0171 ( system too lean, left pank on 4 sensor systems). the car is running very poorly low rpms has little power and traveling up a hill in fifth gear keeping the rmps at a constant 2 grand for about 30 seconds then trying to excelerate from that speed would start to and then I would feel a loss of power and a miss but still would maintain the same speed and rpm even at wot. After that the car will not idle and misses a lot at low rpms, but after continuing to driving it it clears up. I'm at a loss, I checked for intake leaks, throttle body and vacuum leaks , cleaned my maf, checked all connections. Could someone please help me out.