EGT Sensors

[S_W]

Hi, Looking for a bit of advise or help.  Following Engine Control System illuminated lamp an Audi Diagnostic Check identified the G495 fault code, identifying changing Sensor 3.  The test result returned EGT Sensor 1 = 19.975 Deg C, Sensor 3 = 161.10 Deg C and Sensor 4 = 35.475 Deg C all measured at 25 Deg C.

Just wondered if anybody can advise the corresponding sensor ohms measurements for the 25 deg point, as my readings were circa 210 ohms.  Also which sensor (1, 3 or 4) is the pre turbo (black electrical connector), pre DPF (brown electrical connector) and post DPF (orange electrical connector).

Audi Cardiff quoted £354 (parts and labour) in addition to the initial £60 diagnostic check to complete the works, does this sound reasonable?

Many thanks in advance.