My car has just turned 91000 mile DPF light came on , cleared it out by driving it, then it's come back on again, engine management light came on and now glow plug light on and now it's gone into limp mode. Is it ok to drive to the garage? I've read that dpf filter is at end of it's life at 90000 is that right and how much will it cost for new dpf filter? tia.