My cap and rotor are Bosch OE replacements that have been on for about 24K miles. These parts normally last a long time, but my engine developed a slight misfire at idle that caused roughness and increased emissions. The cap terminals bench tested with the proper resistance (I think it's 2K ohms), but on one terminal if I put some side pressure on the tower with my finger, it went open, so there was some internal manufacturing defect that caused an intermittent open and subsequent misfire on that cylinder.

With the new cap and rotor the occasional idle misfire ceased and HC emissions went down.

I'm still looking for input from someone who has removed the fuel pump or OVP relays. Mine don't seem to want to come out without what I consider excess force, and I don't see any release taps in the sockets.

Duke