Let me start by saying I am new to the forum. I've got an 04 3s sedan with close to 80k miles on it. I have beat the living crap out of this car up to this point so I am not at all suprised that I am having this problem. Car has been absolutely great to this point.

Now for the problem. I have been getting misses and fairly severe engine vibration along with a check engine light. I checked the code with my obd2 and it is throwing a code for both cylinder #3 misfire and overly retarded cam timing. Yesterday I tried changing out the coil pack on #3 as my old roommate had the same drivability problems with his mustang and the problem ended up being the packs. However when I changed both the coil pack, and the spark plug out it didn't help. Still throwing the same code and having the same vibrations.

Would anyone have any suggestions other than to take it to the dealership, pay them 120 bucks just to look at it and then who knows how much for the work?

Thanks in advance for any help on input.

 

I'm assuming plugs are gapped OK?

It may be the wires, if they can't get the zap to the plug, the cylinder will most likely misfire.

If plugs, coils and wires are all good, maybe a problem with the cyclinder itself. Cracked cylinder head?

 

I'll still have to check the wires running to the coil pack. Plugs are bosch +4's or something along those lines (4 separate prongs) and are ungapable. I'm going to go into mazda tomorrow and see if I can't talk to one of the techs. I hope to god a new head is not in order.

 

Mazdas don't like Bosch - NGKs are where it's at, because our cars <3 them for some reason.

 

J-Protege is right about the NGK's. I had some in my MSP and the car seemed to fire SO much better than anything else I had tried. Check the wires and if that's not the problem then I'm lost. As far as the vibrations go check your motor mounts. They might be shot. OEM Mazda mounts seem to have a tendency to be weak. Plus they're oil filled so with any spirited driving you can almost count on failure. Especially after 80k.