Engine problem

[quicksilverdon]

Plugs and wires are like chicken soup - can't hurt. I wouldn't go stock, get the Champion platinum plugs & some good aftermarket wires (I got Crane wires from RaceAndStreet).
I had the same symptoms (no check engine light, and very infrequent) at more miles - the wires cured my problem permanently (I'd already done plugs). Might as well do both, since on NA cars the wires & plugs are a pain to get at, so when you take of intake manifold might as well do both. You're going to need them sooner or later, if you get good stuff they'll last.
My opinion.

[BORICUA]

I did the ignition test and I got this code, P0303 Cylinder misfire, so what should i do now?
Excuse my inexpertise but i'm not too familiar with this types of stuff, and that's why i'm asking for some help.
Thanks.

[Cal Cruzer]

I would pull the plugs and see if one looks wet. This would let you know if one is not firing. If one looks bad, I would test/replace wires & plugs. If they all look good, then I would check injector leads. Make sure they are all getting the signal to pulse. But it sounds like you do not have the expertise to do a lot on your car. In the long run, it could be cheaper for you to just have a pro look at it and give you an estimate. (pro does not equate to dealership)

[MX-5]

P0303 means that the crank sensor measured a drop in rpm and calculated load value only during the power stroke from cylinder number 3.
This should mean that the #3 injector is firing. The coil fires 2 cylinders at once, therefore a waste-spark ignition system, so the coil isn't suspect.
That leaves the secondary ignition system, ie: plugs & wires.
Either the wire is faulty or the plug has failed. You can swap the wire from the #2 cylinder to see if the fault code moves to a P0302. But, because you have to remove the intake manifold to replace the plugs, you should do all 4 of them.
The instruction guide is written at www.ptdiy.net

By 15K miles, my first PT plugs had a gap that opened 18% out of specs!

[KingKole02]

My PT has a stubble at 15,000 miles now while at ideal sometimes. I think I will need plugs soon too.

[TripleJackInGA]

If your PT has stubble, you should shave it more often.

BORICUA - Just bring it to the dealer since it's under warranty.This kind of thing is covered.

[BORICUA]

Yeah I'm taking it to the dealer tomorrow and see what they'll say.
Thank You guys for all your help.

[PT-ERA]

Last night I tried the ignition switch trick to see if a trouble code would pop up. I all I got was one word, "done". I assume that means everything is fine with my engine.

[BORICUA]

Ok i took it to the dealer today and yes they removed the plug and found the insulator crackef its all been replaced. Also they told me there was a bulleting from chrysler stating that they been having a lot of this same problem and they are coming out with a new plug to replace the old ones, but they dont't have a date yet, once they're in I can take it back to replace all of them for the new ones.
Bottom line... Problem solved.
And again thank you all.

[IRPT]

Glad you got everything worked out and your PT is up and running again. BTW, didn't happen to get the bulletin number did you?