So i have a 99.5 jetta. car was running great. i let my gf borrow the car and she said she add oil to the car. i guess over by 2 quarts. she parked the car and couldnt get it started. some guy helped her get it started and she drove it back to my house. now that car wont start at all. i turn the key and the car revs up and die within a sec. i replaced the coil pack, cps, spark plugs, spark plug wires, cleaned manifold, cleaned throttle body. car still wont start. i hear a back fire everytime i turn the key. when i step on the gas pedal to try and see if it will stay on with gas pedal down... nothing. doesnt respond to the pedal. i am kind of at a lose. really dont know what else to do. maybe a bad fuel pump? fuel filter? fuel injector? fuel relay? car starts everytime for one sec so im kind of guessing it getting gas but idk. im really at a lose. please help.