[CREWZIN]

The codes don't pop up unless the computer receives a message from one of the sensors. Could they be wrong? Not likely but they can be interpreted differently by different people.

Lets say the timing belt breaks. When that happens the camshaft sensor sees the camshaft isn't turning, the crankshaft sees the crankshaft isn't turning and I'm sure a few other sensors see that something is wrong. The first thing people see is the P0340 and replace the camshaft sensor. It doesn't work and so on until someone puts it all together and comes up with the timing belt.

...and YES, the breakdown of the plugs and wires can cause a whole host of different problems.