Ok, so my car has developed a slight miss in the timing at idle. I've replaced the cap & rotor, wires, plugs, EGR & PCV valves but I still have a slight miss which would appear to be coming from the passenger side. I even took apart the throttle body and gave it a good cleaning and replaced all the gaskets. I've also been replacing suspect looking vac lines, as well as a new EGR and PCV valves with new tubing. Motor has somewhere around 130k to 150k (odometer burned out ) Was looking at replacing the fuel pressure regulator (fuel filter is fairly new) since it looks original and very oxidized. My Dad keeps mentioning a "weak" valve / "sticky" lifter but the car runs really well other than the miss at idle. Can anyone give anymore insight? I think at this point it's either in the fuel system or inside one of the heads.