please can any one help am pulling my hair out here. bought w reg galaxy tdi 130 bhp. loses power quite often when under load cannot go over 2500 revs its like the turbo is no longer there . when i switch engine off and on problem is sorted back up to full power. so far i have replaced the m. a. f with no effect. air filter changed ...improved power but no change to problem. was told it was fuel filter ...changed that........no change have checked all pipes for splits and all are fine have been told it could be throttle position sensor but is