i have a 2002 grand prix gtp 40th anniversary and it failed etest really bad, found out i had an intake leak,so i changed upper and lower,did plugs and wires cause they were bad too and oil and coolant. now the car runs crappy,blows black smoke sometimes,stalls while driving and i ran codes and got code 101 and 140,one meaning o2 sensor #2 and performance problems with the maf sensor, but the weird thing is it never did any of this before the intake gaskets were changed and my boost guage doesnt show any boost either.....plz help
