Car stalls

Have the vehicles's PCM read for fault codes and get back to us with the codes. Most good autoparts stores (autozone etc.) Do this for free.

A few things could cause this. First, the fuel pump may be going bad. I recommend having fuel pressure checked. If you need directions, let me know. Next, the catalytic converter could be starting to plug. If this happens again, check to see if it is red hot. If it is, replace it.

Let me know what you find.

Joe

Sounds like internal motor damage. Have it tested for engine compression. You might need an engine rebuild.

Check for vacuum leaks and check the idle air control valve. (IAC)

Could be the TPS indeed. Back probe the wires at the sensor, One is your ground (around 0V), another one is your hot wire (about 5V), and the last one is your signal wire. When you open the throttle, the voltage at the signal wire should go up steadily until 5V (fully open). When you close the throttle, the voltage should drop back down steadily. If it doesn't go up and down steadily, but rather jump from say 1V to 4 V all of a sudden, that indicates a bad TPS.
You can also disconnect your TPS and put a ohmmeter across your signal and supply wires. As you manually open and close the throttle, the resistance should increase and drop. If you have erratic readings, the sensor is bad.

P.S: I would also check the fuel pressure to make sure there's nothing wrong with that.

Either you have a vacuum leak or the IAC is bad. Keep in mind, WD40 is a lubricant and not a cleaner.