hi sorry have not replied to responses sooner but would like something positive to submit.we had 10 psi at cruise on a guage we rigged up to the pressure sensor ,this related to 3.8v when measured with voltmeter on middle terminal.at idle pressure was 5-6 psi and sensor output was 3.5v.i thought that was too much pressure and not enough spread of voltage for a normal sensor reading.i scoped the injectors looking for an extra post injection phase but all was normal according to picos piezo injector patterns so have ruled out over fuelling for the moment.removed catalyst rechecked pressures no back pressure present refitted cat back pressure returned.removed cat again and this time removed dpf ran the car whilst watching output from turbo and a stream of black engine oil evident.no play is evident on the spindle the oil seems to be coming from behind a cylindrical insert close to the rotor but i could be wrong as the air flow through the turbo diffuses it quite a lot.we are at present fitting a new garrett turbo etc so will reply hopefully with a fixed in the next day or so.the glow plug fault seems to be the controller/relay under the inlet manifold as all the injectors checked out ok (5v).a new relay illuminates a test bulb ok.thanks for replies regards paul ps we are rodding out the catalyst as opposed to renewing it to see what the results may be