Intermittent Misfire 07 nissan quest
 

This happens every now and then. We are driving down the road and suddenly the van starts to bog down and misfires. Can't go over 50 when this happens. We have been smelling a random burning electric smells But that is very random. Also when the misfire happens the cel blinks. But by the time I get to where I can stop and check the codes out its gone Please help. It has the 3.5 v6.