Hey everyone I am new to the forum. I am having trouble with my grand prix gtp i just bought. It is a 99' GTP 3.8L supercharged. I have been working on cars a while so im not clueless but I am stumped. The car keeps setting MAF codes along with TP sensor codes. Both sensors have been replaced. The car will die intermittently after about 35 min of driving. If I pull over and clear the codes the car will run fine for a little bit or as long as a few days. I have performed throttle body clean. I just replaced battery. When I unplug the maf it runs worse sometimes and not other times. same with the tps its very inconsistant. I have also had a cat effiency code and a trans pressure solenoid code but i cleared that initally when i bought the car and hasnt came back yet. I am thinking maybe PCM or MAp sensor. I dont have tech2 available. PLEASE HELP also its seems sometimes when i am driving down the highway it will feel as though something engages and takes power away. the rans will shift way too firmly and if i come to a stop i will have to double foot the pedals or it will die