Hi, well after 6 months and lots of money being spent, my Subaru is finally back on the road

. Only issue left Is that after new engine and decat system being fitted my mechanic plugged the car in to clear the fault codes, managed to clear the knock sensor and the lambda sensor , but there is another fault , he looked it up and found it's the "tumbler generator left hand #2" looked on the Internet and it's coming up as a £300 part! But several forums ect say it does not effect the running of the car in anyway is this correct?
Also found that the ecu can be flashed to remove the fault permantly?
The car will need a remap once iv run the engine in anyway as it's severely over-fueled so if that's correct it could be done at the same time?
Like I say the car seems to be running fine even with this fault and my mechanic says he's never heard of the part and doesnt have a clue way it does lol.
Cheers, Nick