misfireing

Hi, I've recently EGR deleted, downpiped and stage 1 tuned my 105 BLS 1.9 TDI However now i have a probelm that accures every 300 km. It will begin to misfire and produce tons of blue smoke for about 10-15km. And suddenly returns to normal with no misfiring. Anyone know my problem? My own guess...

if i drive my car like a pansy its alrite but if i put the boot down it jus misfires and splutters up the revs i.ve changed plugs and leads and the coil pack its only got a new distributor aswell so any help would b gratefully apprectiated

Cars booked into garage on friday as its misfireing badly and engine lights on. I think its the coil pack but wondered if i can drive it to the garage as it is, or if i need to get it towed. Any help would be much appreciated, cheers.