New guy needs help!!! P0302 misfire Options

[freeriders98]

So I just picked up a 96 GT. Guy I got it from said it had a rough idle and check engine light would come on occasionally. Had a rough idle, but CEL was off when I test drove it. Of course it showed up the next morning...

So here is what I know now. CEL is throwing a P0302 code. It only happens if I let it idle for a bit, like warming it up on a cold morning. Before I drove it home after buying it (4hr drive) I cleared the light it and it never came on.

At idle it is rough, but as soon as it comes about 1000rpm it smooths right out and runs really nice.

I checked the plugs today, all looked good. It has midgrade NGK's in it.

I've been looking for some pointers for a couple days now, and have searched on here.

Most reference a coil/plug set-up. So does my Celica have just a standard single ignition coil mounted on the fire wall?

How likely is it that plug wires are my issue? The ones on it are tiny and look to be a generic set. Would a set of better insulated NGK wires help? I know that wires can get interference and cause some firing issues if not well enough insulated.

And help or input would be great. I'd like to at least narrow it down to 1 or 2 things before I start throwing money at it.

[freeriders98]

I've got a Wells brand Cap and rotor coming, along with a new set of plugs. I've got 2 days left of work before 4 days off. So I'll take a look at the injector oring for damage and run some seafoam through the brake booster vacuum line.

Thanks again for the help and direction.