The engine was running fine when I drove into the garage. Then, when I went to start it to move it a bit, it wouldn't start.

After researching on the net, I replaced the crank and cam shaft position sensors, then also switched the ASD (Auto Shut Down) relay with another one in the fuse block (both had the same part number and pin arrangement). Also tried flipping the door lock back and forth to reset the burglar alarm. But no luck... the engine turns over and starts to fire sometimes, but doesn't run.

Any help is greatly appreciated.

What year Intrepid?

I would:

. Check all under hood and under dash fuses with a test light or multimeter.

. Check for codes and pending codes, using an advanced scan tool.

. Verify that you can hear the fuel pump run, when the ignition switch is turned to ON.

. Verify that there's plenty of fuel in the gas tank.

. Verify that the Check Engine Light comes on and goes off, when the ignition switch is turned to ON.

. Check for good, solid spark.

. Disconnect the negative battery terminal and clean the main PCM ground.

If the problem persists, I suspect the security system.