Just bought my first trans am after wanting one for over 10 years. 97 Ws6 Lt1 91,000 miles. So anyway I bought the car 3 months ago and it ran great, recently it has been hard to start ( I have to prime it about 5 times before it will turn over) and it has been throwing a p1642 and p0308 code. Changed all the plugs and wires along with VSS and still no change. It is surging in 5th and 6th under load and it has a miss at idle and also has a slight miss while driving. I have also changed the ignition coil and EVAP solenoid as well because it was throwing a code for that also. Any help would be appreciated, thanks

Would that cause the 1642 code?