Hi I had posted previously about my 2011 CLS 350 (218) which had an odd limp mode (no dash lights) and came up with a Y77/1 Boost pressure positioner is faulty error code. My local indy said I needed a new turbo based on this, however after some advice on here I pursued replacing the turbo actuator - which I have just completed this morning (I bought a reconditioned one from turbo vanes) - I also replaced the seal on the main turbo inlet as it was worn, and the one on that breather to the left side of the batwing assembly. All went well... however after a 25 mile test drive and some kicking down to check the turbo was working ok, the car went into limp again, no dash lights. The error code above shows on my cheapo OBD scanner - 'The positive control deviation during boost pressure control is too high'. When I restart the car or clear the code it worked fine - but did the same on another test drive. Any ideas on what this could be? Thanks Phil