Ok on my 96 disco I was doing some work and I noticed the hose that goes to my valve cover passenger side was off. its in rough shape but was able to salvage it for now. I also noticed the oil separator was way dirty,. would having that hose off effect the vehicles performance, I put the hose back on i haven't drove it yet since I hooked the hose back up. and how often should you clean or replace the oil separator.

 

Yes, buy both the valve cover hoses, clean that strainer and clean the throttle body and IACV, probly all dirty