Freelander td4es revs keep droping help pls
 

Hi I've got a 2001 freelander td4es it stats and drives fine but every now and a gain when I stop at light ,junctions etc or when just stoped with engine still on the revs drop and some times cuts out but it will start straight back up I've did have a problem with a noise when I would turn car off it would make a loud virbrateing noise thought it was the egr solenoid when I removed the solenoid I found out that it wasn't the solenoid it was a nail in the pipe that went from the egr to this solenoid so I removed it noise gone but still keeps droping revs also had it computer for dianotics and it's saying that they no problems can anyone help pls