Anybody have any suggestions on what would cause a misfire in the #3 cylinder? Dealer said he thought there was one. Plugs, wires and injector all working properly.

 

Did you swap the plugs, wires, and injectors around...and still get a misfire on #3?

If so, I'd have to say the opti could be at fault.

 

Start the car up and check under the hood while it's pitch black dark outside. Look for some faint blue light coming from near the wires, it could be grounding out on the manifold.

Otherwise if you're sure it's not a bad plug or something, it's probably the opti.