My 1.9Tdi 130, loses power when accelerating. Which I think is either a vac or boost leak or could be due to recently by-passing the EGR. Are there any simple ways of checking for a vac or boost leak? Originally I was getting a massive loss of power between 1500-2000rpm followed by a sudden surge of power and some black smoke out of the exhaust. I decided to by-pass my EGR just using a golf tee pushed into the egr vac hose, this seemed to cure the loss of power for a few days until a similar problem started. The loss of power now isnât as bad as before and it occurs at a higher but broader rev range. Iâm not sure if this has come about as a result of by-passing the EGR without blanking it or whether itâs something Iâve done since whilst tinkering with some of the vac hoses. Before bypassing the EGR the garage where I had the car serviced suggested that the (original) problem may be due to a vac leak and gave me a bit of new hose. After by-passing the EGR I thought I might as well make use of the new hose but I only had enough to replace a couple of hoses, so I tried to find the ones which were least awkward. It was after this that the car started to struggle with power again. I suspect I may have snagged something and caused a vac leak. Or I may have caused a boost leak, since I was flexing the pipe from the MAF sensor to the turbo for better access, whilst renewing some of the vac hoses.