Amazing post, spent the last 6 years trying to solve the same problems on long journeys, tried new fuel filters, cleaning out fuel tank, cleaning maf sensor(several times!) new air filters, replaced turbo rubber gator to air filter, all to no avail.. This seems to have cured it, actuator was bouncing up and down a few mm before I changed the part then was solid afterwards, taken car on a long blast and so far no limp mode! Hurahh! Thank you!!!