Ok chaps, is there an OBD2 plug on my wagon, will a plug in tuning box work? If not what will. There are lots of £80 boxes on eBay but not for my model?
What's my options.
Pros and cons on egr removal as well please as I noticed a broken wire on my egr vale plug so it's probably not working even though I don't get an eml light coming on.
One last thing how do I test my glow plugs as its a sluggish starter.
Cheers!

What year truck? That will make a difference to all the othe answers

think it's a 55 plate classic @tigger
the only boxes that work on a classic I believe are the ralitronic and genuine mitsubishi ones
genuine one will set you back nearer 200 quid
if it's a bit more 'umph' you're after I took the egr and cooler off mine, fitted a K&N filter and removed the cat and it was as if I'd been driving with the handbrake on for years then suddenly taken it off (keep your old cat though as MOT requirements change over the years and may only be a matter of time till they are compulsory)
EGR valve basically puts burn exhaust gasses back into the engine a second time to 'reduce emissions' although when I removed mine my emissions went down slightly
having a stuck valve can cause other issues that @ronniecabers will confirm
having an EGR cooler go porous will introduce hot gasses into the cooling system and most likely lead to head gasket failure
removing the cooler , valve and unplugging the sensor wont through up any eml lights
dont know how to test the glow plugs but turning the ignition on then waiting for the click, then turning off and repeating the sequence should help your truck start if your plugs are on the way out. Obviously 'burning' them twice will decrease their life if they are on their way so this may show you the problem not cure it (not in the long term anyway)

Ok where's best for an egr blank kit then?

just tap in l200 egr blank on ebay or the like
kit should have 2 blanking plates, 2 bots, 2 washers and 2 nuts. Also a little cap thingy for the vac pipe (I lost mine so stuck a bolt in it instead). Some come with gaskets but I reused the old ones that were on there.
you'll also need a length of pipe to join or replace the ones that go to the cooler

Blanking it is definetly best ....if it sticks you got huge loss of power , like the handbrake is on , a lot of black smoke and very quickly it doesn't want to start! but no EML

Yep exactly what Mr Krutters said