Have a turbo kit installed on my 03 EX and it's running rough....mechanic says I need a new 02 sensor (both) and a new map sensor to fully diagnos the problem.

As I bought the car this way last June, I have no idea if this is accurate or not, and the parts and labor gonna run me $350. Then they say they will be able to tell me the problem, which could cost me god knows what.

So my question is, with a turbo kit installed, would these parts be required to perform the diagnostics? Or are they not understanding how the turbo could be affecting their diagnosis?