No Start condition

One day i parked my car and when i wanted to start it it just would not start. i tried several times and eventually it did. Then i took it to a mechanic, the ran the scanner and show ABS fault and transponder not recognized, but the Pats led never blinked rapidly. The mechanic changed the crankshaft sensor and it wont start right away. He said that if i leave the key in run position for over a minute it will start, so i did that, it worked like two weeks and now the car is in a no start condition (I called a locksmith and got the keys re-programmed). There is gas in the injector system, i check the coil circuit and it has power but there is no spark. I switched the relays of the PCM and the fuel pump and still no start.
I do not know if i properly checked for spark, i used two methods, one with a light tester and one putting the coil on plug near a bolt and non of them gave a positive test.
Any suggestions?