Alan. Get a cat bypass pipe. I got mine from Ed Uding in the Netherlands at a very reasonable price. When my cat decided to dumps its innards into the silencer I had not recognized it as part of my problems. The car overheated, and generally ran with less oomph then I had expected. The running problems got worse to the point where I couldn't rev it at all and it was unusable. In the meantime the act of trying to run it meant that the heat built up in the silencer, the original asbestos heat shield disintegrated and the bumper started to distort! New silencer (thanks again Chris) and bypass and now the car runs really well. Very smooth and much quieted than before. I left it too late, my original silencer is now beyond repair?. I now have a whole new set of quirks, but the car is once again on the road!