slight misfire

Hi
when i am traveling at motorway speed my td5 seems to have a slight misfire,
this only happens at 70 - 80 mph, my first thought are towards the injector loom which i have read about giving problems. How big a job is it to remove this loom to inspect it, any special tools required ?. Grateful for any tips i was ok with my 200tdi but this is a different animal.

Open the battery box cover and look down at the ecu. If it's wet, you have an oil cooled ECU.

Or remove the 3 bolts that hold the engine cover on, take the cover off, and unplug from the front o/s of the head. Any oil and it's a leaky loom.

Rob

Thanks for that the plug seems clean, another thought is i have blanked off the egr valve at the exhaust but have not removed the valve itself. If this was not working properly would it cause a problem with the engine.