Po300???
 

Just got the car back from the body shop yesterday, ran fine, went to my buddies house, a few hrs later left and on the way home from idle to about 2500rpm's it would stumble bad, felt like it was falling on it face and even the exhuast sounds different.. Next day (today) also same thing runs like a champ when cold. gets warm stumble again... well I put a msd6a in today and it once again ran great cold, ran like crap warmed up... now po300 comes up twice.. What do I look for? Coil? Plug wires are not touching up anyways.. the boots of the wires seems to be trying to ground themselves to my tr55's, will a lil die-electric grease help that? I have no spark from wire to wire... (arching ?) I'm lost. please help. and I did a search of po300 to find nothing that was helpful. ... thanks

Keith, P0300 is a random misfire code. Sounds like your wires or (hopefully not), opti.

shouldnt be my opti Ion, at least I hope not, I just put it in last thanksgiving.. Maybe 12-15k on it since.. sounds like the wires then huh? I got a set of 8mm taylors in the closet thank god. i bought as a spare.. :) Would the MSD box do that?

You said it did it before and after the MSD box, so it doesn't look like that is the trouble. Start with the coil wire and then plug wires. Maybe even meter each one out.

How can you tell if the coil wire is bad?

And if I meter them? Multimeter? What setting and what ohm? should it be at? Thanks a bunch... :)

TTT for the early am guys, I'm gonna be working on this around 11 so I'd like to get a hint of what to look for and how to check the wires ohm's What will a good wire read vs a bad wire?

Most DMMs have an auto ranging feature. If not, just start at a medium high scale, then go down as needed to get a better reading.
The resistance reading will depend on the brand/kind of wire. Stock wires can be more than 1k ohms/ft or higher. Some aftermarket ones can be 100 ohms/ft or lower. The factory manual says a coil wire is not considered bad unless it is over 30k ohms. That seems like a lot. I doubt you will see a reading that high.
It is best to compare the wires on your car to each other. I am sure they are not all bad, but you will easily spot a bad one, because the reading will be way different.

how do you read the ohms? I took 1 wire off at a time.. put one end on each end and the meter goes all the way up, for one wire it only went like 3/4 up? is that a bad wire? I had one wire cracked n burnt and it still read up all the way? if you touch the two ends of the meter together it goes all the way up too? am i doin this right? please help, i started it after doing the one side and its still crappy as hell if not WORSE.. should I just replace em all ? I'm gettin pissed quick as hell out there.. stupid car! Please help

I replaced two wires on the driver side and had 2 loose plugs on the pass side... Still runs like ass. it even sounds different... I unhooked the msd box.. sounded different again... I dunno. I need help...:( Just got it back from the body shop, looks like a frikin brand new car and I cant even drive the thing... If my o2's were that bad, would they cause it to run like crap? I think it maynot be running on all cylinders. how do you check for that?

Gonna replace coil today and the other 2 wires on the drivers side.. Wish me luck! I need it !!