I don't really know if there is any way of checking them. I knwo when I first got my car and it died randomly, I had it brought into a local shop and hooked a SHITLOAD of sensors up to it and had to let it run for 2 hours on the lift before it killed again and they figured out it was the ECU. So unless you have a million different testors, I'd try find one somewhere that you could swap in to test.