ive recently bought 53 plate signum elite,75k on the clock
I get a misfire / rough running between 60 -75mph and 3k - 4k rpm.
The fuel pump is already a Continental and Vauxhall say all recalls including the FPR have been carried out.
The fault codes on it are P0403 Powertrain - exhaust gas recirculation control unit, and P0301 cylinder 1 misfire.
I've blanked off the EGR outlet pipe where it connects to the head today and changed the plugs but it hasnt made much of a difference. I'm assuming this P0403 could be the culprit - can I just disconnect its wiring or does the unit have to be physically removed and if it does do I need Tech 2 to tell it its disconnected or could I use an OP-COM to do it?
Also the temperature guage rarely moves from zero so i have a new sender on order but it makes me wonder if it thermostat was causing the rough running?
Anyone any ideas?