2004 Mazda 6

Electrical problem
2004 Mazda 6 6 cyl Front Wheel Drive Automatic 110000 miles

I have 2004 Mazda 6 3.0 L. I have an intermittent jumping in the trans or engine. Check engine light came on and coded P340 Cam Sensor 2. I replaced both Cam sensors 1 and 2 and have the same problem resulting. Drove it around the block and check light and traction control light were lit and the same codes. It seems to happen more often when it is damp or humid out but really does not matter on the weather. All these problems arose after I had my spark plugs changed. Check engine light came on and said cylinder 2 misfire. Took back to dealership and they said it might be coilpack, so I replaced that then the send my car coded for a throttle body. I had them clear the throttle body code and never came on since but I have been having this cam sensor issue and bucking of the car. My car ran perfectly fine until the plugs were changed. Any suggestions?
June 8, 2009.

Aug 18, 2009.