P0305 HELP!!!!

[98DC]

About a month ago, I got a P0300, I took the car to the shop, they changed the coil packs and the code and misfiring went away.

Now to present day, I was driving home and it started to misfire again, I checked the code and this time I got a P0305. So I got new plugs and wires and spent several hours changing them out. (Number 3 is a complete PITA!) I started it up and it seemed ok, I took it around the block and the misfiring was back with a vengeance, The check light came back on and it’s giving me the P0305 again.

I’m lost here, I don’t want take it back to the shop, I have the time to fix it this time around. What else should I check / replace??

[98DC]

I got this from obd-codes.com.
A code P0305 may mean that one or more of the following has happened:

Faulty spark plug or wire - Done
Faulty coil (pack) - Done
Faulty oxygen sensor(s)
Faulty fuel injector
Burned exhaust valve
Faulty catalytic converter(s)
Running out of fuel
Poor compression
Defective computer

I know what to look at but still need dirrection. Any suggestion on what I should start with first?

[geocor]

How about a compression check on that cyl.?But first I would do a simple check to see if the plug wire is on tight,it could be as simple as that,it happened to me.Switch those 2 cyl.wires on the coil,take the plug out to read it,(how did the old one look when you replaced it?).Not enough info here on history,ie. miles,oil consumption,or coolant low level?Start out with the obviuos,& keep us informed on progress.

[98DC]

It has 72k, nothing big on the oil and everything was sat with the plugs and wires.

It has become a reality (sadly) that I need to sell it, So working on it my self just doesn't make any since. Just going to take it in on monday get it fixed and let it go....

[Camaro Dom]

Originally posted by 98DC:
It has 72k, nothing big on the oil and everything was sat with the plugs and wires.

It has become a reality (sadly) that I need to sell it, So working on it my self just doesn't make any since. Just going to take it in on monday get it fixed and let it go....

mmm... well, let us know what the verdict is... hopefully in the future you'll get another f-body. good luck man.