buy new cam sensors? please help!

[SaTownPathy2k1]

The SES light came on for my 01 Pathy 2WD LE. The touble codes I received are P1110 and P1135 - Intake Valve Timing Control (left and right bank).

I recently had the FRONT crank sensor replaced and I have been told by my mechanic that it would be best to replace the 2 cam sensors and the REAR crank sensor to fix the problem and keep the SES light from setting off.

Is this correct? Has anyone out there come accross this similar issue? What should I instruct the mechanic to do? I am trying to aviod unecessary repair bills. My Pathy runs fine and I do not notice anything wrong with it, but that F'n SES light will not stay off!!! Anyone, please give me some advice, thanks!