I got my car pretty much apart because my water pump was leaking and i was replacing it. I think my opti is dead because i was having misfire problems lately and sucky gas mileage 13mpg on premium and just about everything else is changed. It would make sense that the coolant leaked onto the opti.

I do have a burnt wire which i changed and had a loose spark plug which i will tighten tomorrow. How do i tell if the opti is good of bad?

 

one way would be to see if you have spark coming from the coil wire.

see if this heres also: http://shbox.com/1/4th_gen_tech2.html#opti_test

 

The way I figured out was replacing mine.

-Dustin-

 

Grab the coil wire and spin it over,if you don't feel anything it's dead.On the other hand if it ain't dead you will be picking yourself up off of the ground.
Thats a real sure way to test it and you asked for a sure way.
Otherwise hold the coil wire about 3/8" from any grounded metal and it should jump with a bright blue color, no orange. That does not mean that the fire is getting to all 8 cyls.The cap and rotor may be TU.