Do you need to change both coil packs or can you change just one? I keep getting a misfire code on cylinder 1 and 6 and I think it's the coil going bad since they are both on the same one. I just put new plugs and wires on and reseated all the wires and still get the code. It's making me nuts because it hesitates when you first hit the gas and then it takes off. It seems OK at highway speeds until it downshifts then it surges and hesitates, etc, etc. The only thing I can figure would be the coil packs. This is on a '99 4.6L BTW.

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I know that on my wifes grand Am we replaced only one of the possible three. This was done by a certified mechanic. If you are planning to go with factory I would say it would be okay to replace one because you are pushing the same amount of volts and spark. If you plan to go with an aftermarket one such as MSD or Accel I would change them both because you are getting a better spark

 

Holy crap, what a difference that made! It's like going from a 4 banger to a V8! That was definitely the problem.

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what exactly did you change? My truck is doing exactly what you describe yours as doing. Feels like a miss or something and then when you get going it takes off. do you have a computer to diagnose your truck with or how did you determine where the problem was.

 

I kept getting a CEL and went to autozone and had them pull the code. It was cyclinder a 1 and 6 misfire, and they just happen to be on the same coil. I replaced that coil and now she runs great! It started with a misfire on cyclinder 1 only so I changed the plugs and wires and still got the misfire code. I would check your coils.

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