Dont think your misfire will have damaged the EGR valve but think your smoke problem will have improved,maybe worth getting a code reader onto it for a look at codes stored and you didn`t say if you had changed the fuel filter or checked your valve timing,if your timing chain is at fault you may hear a tinkling from that side of the engine,have had crankshaft sensors away on these,at front of engine half way up the block near g/box,torx 30 screw holds it on,maybe worth a look but not had many injectors or high pressure pumps away on these,just leaky pumps but the motors still run ok,maybe a compression test would point out a low compression on a cyl. also but maybe it would be worth getting Tech2 put onto it first for a look at DTC`s,good luck
wickham
June 2010