I wonder if the "pcv" valve enters into the problem, ir has a connector attached and goes into the intake tract after the MAF, does anyone know what the pcv sensor does? I have a catch tank attached to the pcv line to trap some of the oil, but it's been on for over 140000 miles and never had a problem, I replaced the turbo inlet O ring, and the O ring on the pcv valve that goes into the intake tract, which is after the MAF, the tract shows no tears or holes, the pcv looks like a clear shot through, no valve or flapper, has a 2 wire connector attached. Car pulls cleanly to redline, vag-com graphing shows boost and MAF responding with load and rpm changes, no ziggly responses, the code usually comes at cruising, steady speed and rpm, does not happen on fast starts and pulling to redline. Any thoughts?