Re: 74mm Throttle Body, surging idle
Mine was doing the exact same thing when I first did the TB upgrade (A while back so memory is not really clear on all I did to fix it.)
I know I retorqued the TB to 7.5 foot lbs I think it was, did another TB reset and everything was good to go from then on
I think the first time I had the torque wrench set wrong.