The slight misfire and the steam could be connected. Look around with a torch for any coolant stains around any of the COPs, but particularly check the rearmost COP on the passenger side by removing the 7mm securing bolt and pulling the COP off the plug. Ant sign of water in the plug recess, or wetness on the rubber shaft of the COP? That plug often gets it being "fed" water by leaky screen-wash jet, or in other cases if the intake manifold gasket is leaky. If the intake has ever been disturbed, the rearmost bolt near that COP is difficult to torque down correctly (access), particularly the final "warm" re-torque, and often gets "forgotten".
A 4mm hole in the EGR blanking plate is a good idea, and may well help with the EML light, if indeed that is the reason for it coming on.
Would be nice to have some pictures of the car, Gaz, if possible (blue by any chance?). What are the last 3 characters of the VIN?
Knowing that my also help to trace past owners on the Forum, and reveal any otherwise undocumented problems or work done in the past. Finally, and most importantly, make sure you join up now as a full member. Until you are 'green' you will not be able to access loads of technical information here to help with the niggles you have. Just PM or email Tim and ask for a questionnaire to be sent to your email-address.
