Hello, Just joined the TDI forum. This looks to be a very informational site, and I appreciate the time people take to help one another. I recently purchased a 06 Jetta TDI w/130K. Vehicle ran great for several weeks then the service engine light began illuminating with Code P0101 MAF. Replaced air filter and reset code. 300 miles later another P0101. Started doing some research on probable causes and 150-200 miles later vehicle went into safe mode on way to work. Turned off checked oil, coolant, etc. and restarted vehicle to drive back home. Vehicle began to run very poorly with heavy black smoke in RPM band from 1500-2000. Power was deteriorating and within 10 miles seemed to be running on 3 cyl. Turned off vehicle, towed home and it is now in my workshop awaiting my attention. I thought I'd begin with an inspection of the timing belt and camshaft. I've heard these engines have a history with cam lobe failure. Although that seem like a very rapid deterioration of performance. The vehicle was getting 48 mpg the last tank prior to this issue.