So here's one for the WG and Diverter Vale experts. I've been having issues with underboost, CELs and P0299 codes that I'm trying to run down. Other than the DV+ the turbo and associated plumbing is stock. Today, just for giggles, I swapped out my GFB DV+ for a stock unit I had lying around. Other than the mediocre performance that the stock DV provides, the car is now holding boost and no CELs yet, after some hard driving. I was a bit surprised, and a visual once-over of the GFB part didn't show any obvious issue. The DV+ is probably four years old and had been working fine. The only thing I haven't done since installation, is to re-lubricate the piston. I assumed that the initial application of oil combined with what it would pick up in ordinary use would have kept the piston adequately lubed. Is it possible that the piston simply got stuck? Anyone else have issues with the DV+. I'm hesitant to reinstall it without knowing for certain whether it was the cause of the problems I've been having. Anyone else encounter problems with the DV+ that would cause the engine not to hold any boost at all? Thanks.