How do i get car to run for more than 5 seconds?

first i would check for fuel,you need to have someone hook up a fuel pressure guage it should be around 40 psi at start. if not change the fuel filter if it still does the same thing check the fuel pump ,you should have 12 volts at the purple wire near the gas tank with the key on the first 5 seconds,you should be able to hear it come on by turning the ignition on without turning the motor if not pump is bad

checked all that and was okay. Had to change throttle positioning sensor.

Sounds like maybe your anti-theft system is kicking in. Have you tried another key? Seems odd that it would suddenly start acting up, but then again it is an electronic system in an American made car. Need I say more?

not the anti theft that just would cut fuel off at start way before 5 seconds. if there is some relearns for idle air or otherwise with changing tps they may not have been done at that time. did you chech mass airflow meter may be dirty.