I have an 08 chevy impala, i changed my spark plugs and now its misfiring. Can anyone let me know why its doing that, i had oldschool cars changed those plugs and they run like new, can anyone tell me whats wrong?
What engine do you have 3.9 or 3.5? You may have gotten a bad spark plug. Pull one wire off at a time to see if there is any change in the way the engine idles. If you pull the wire off the plug that is bad there will be no change in the way the engine runs.
timing does not change from changing your plugs. I asked what type of plugs to see if they were cheepos. like cdminter59 says check the plugs. Also are you sure you have the wires correct and on tight.