The error codes from 97 Maxima were "Cylinder 5 Misfire" (06 04)and "Ignition Signal Circuit" (02 01).
I've come here and searched for threads aboud cylinder misfires,
but none of them mentioned any thing about the second error code. I've went in to check the cylinder 5, and found that the coil and ignition were all wet with fuel. I cleaned out the fuel, reset the ECU, and tried it out. The car ran great for like 30 mins and then the problem came back.
I can only think of
sparkplugs (which I just changed a month ago)
coils
injectors
I doubt it's the wiring going to the coils because it worked fine (temporarily) after I clear out the gasoline in the coil/sparkplug chamber. I'll swap the coils with another cylinder and see if it helps, but how could I test the injectors? Are there one for each cylinders? How much do they cost?

any help would be appreciated,

 

there are 6 fuel injectors, one for each cylinder...you can check to see if it is working by puttin a stethoscope against each injector and listen for a clickin sound (when engine is running)

 

thanks for the quick reply!
I didn't have a stethoscope, but a long ratchet worked fine for the purpose. The thing is, I couldn't check the 5th cylinder fuel injector cuz of the manifold covering it. Should there be way to somehow go without removing the manifold to check the fuel injector? If I take it off, I won't be able to run the engine too...