Go to a Pontiac Mechanic and spend a few bucks.
you plunem is leaking and is not chep to fix
Is this a 2003 Pontiac Bonneville? I need this answered for this year and make.
Fix It.
po 302 is not a valid code but maybe misfire code number 2 cylinder
Had a tune-up lately-used fuel injection cleaner lately.
See the answer to 2000 Bonneville Neutral Safety Switch Location. Had the same problem and that was my fix. You can install a separate Start Button in the Starter circuit to start the car also.
buy a hanes manual at oreilly auto parts. cost about $16 it will show you how to fix all problems on your car.
about $150 for the alternator and 1/2 hr labor or shop minimum charge - my guess $215 - $225
If all don't work - check the fuse in the power distribution block under hood- If only one is out check to see if the motor is getting power - if so probably a bad motor if not probably a bad switch or open wire
Had the problem with Bonneville not starting....turned out to be the security module. Your mechanic should be able to bypass the security module with a $15 part from Radio Shack. Pretty easy fix.
drop the gas tank and change the sending unit