I have been having major intermittent misfires on 2 or more cylinders. I have gone through almost everything from timing to ignition. Now i check my not so old spark plug wires. (spark plugs are brand new)

So the spec for resistance on spark plug wires is 25k ohms. I measured 2 of them close to spec ~ 24.5k Ohms. Others measured 12.5k, 13.5k, 5.5k, 5.4k. The shorter wires on the drivers side measured the lowest resistances.

The FSM just says "If out of spec, replace", but my question is: Is low resistance really a bad thing?

 

not a bad thing on the shorter wires. It's a linear thing so the shorter the length the less the resistance. If the wires are from a "cheap source" like O'reillys or Autobone then you might consider getting a good set from the dealer or an online discount operation like
http://www.toyotapartsdeal.com/ It coukd be the cause of your codes on whatever engine you have.

Low resistance means more amperage....means faster erosion of the center electrode in theory.

 

Like Zuk says ^^^
My shortest wire (22RE) has 3.5K ohms. No issues with ignition that I notice, and I get 18-22 MPG. IIRC they're N-Denso's.
Yes, toyotapartsdeal (formerly Toyota Parts Zone) is great online store.
I got my ignition wires from sparkplugs.com - also a good source.

 

The major reason sparkplug wires have resistance is to control radio-frequency interference (caused by the high current spike). You can use pure copper in the spark plug wires and it will work, but neither you nor anyone around you will be able to listen to an AM radio.

ZUK is correct, though, that by limiting the interference-causing current spike, resistance wires also help lengthen the life of the plugs.