Testing injectors?

Saw on a thread that my misfire problem could be an injector

How do you test injectors?

Said to use a screwdriver and listen for "click" but not very descriptive on how to

Also if you were going to use a fuel system cleaner through it, which one?
Berryman's?
It had a can of seafoam last tank full

Miss comes and goes, you can see what I have done here

http://www.tacomaworld.com/forum/1st-gen-tacomas/331014-99-sr5-v6-running-rough-missing.html

 

First thing,I am not a pro! Have been down this road though.Did you unplug and reattach each injector plug? Check all wires related for bad ground?clean air intake system good?Clean throttle body good? So you can start the engine and take a long screwdriver and put tip against injector body. Press ear against screwdriver and listen for clicking sound. If they all don't sound the same could be faulty injector. Before replacing you have to check electrical connectors.There is a light think it is called "noid" that you plug into each injector plug.If it blinks then it has proper voltage. Can also use an ohmmeter to measure resistance with engine off.

 

You use the screw driver as a stethoscope. Get a long screw driver and put the blade end on top of the injector with your ear on the handle end. You should be able to hear a series of clicking as the injectors open and close to shoot fuel into the cylinders.

 

Thanks

Freaking come and go issue with no code is driving me nuts

Not sure what to make of problem but thought I might as well check injectors