just had a diagnostic and gave me these codes 08 phase sensor 136 phase sensor 138 overboost strategy and 05 engine speed sensor circuit. what do the phase sensors do i know how to locate it on the car just want to know if it will sort out the low power in low revs also what are the other two sensors and how do i fix them car going in for a compression test friday to make sure the valves arent the problem any help would be greatly appreciated 
