I took my car to the dealer and they installed a motorcraft spark plug into only one of the cylinders. I have the autolite double plats in the other 5 cylinders. My car now bucks in third gear and I don't know if one different spark plug could cause this or not. Also they changed the fuel pump, fuel filter, and an o2 sensor. Do you guys think its the spark plug or did they just not connect something right. My car wasn't bucking before I took it in.
Thanks
