My check engine light turns on and off, I haven't noticed anything major with the exception of mild shaking of the car when the light is on. I had it diagnoses and was told it was the spark plugs, replaced those but nothing has changed.

 

There is no diagnostic code that states the spark plugs are bad. I suspect you had a misfire code, but that by no means says the spark plugs are the problem (although that's typically the easiest and least expensive place to start if one is going to shotgun the issue). A misfire could also be caused by one or more bad coils, a bad or poorly performing fuel injector, a vacuum leak, etc.

My suggestion would be to get the actual diagnostic code number and report that code back here for further suggestions, or take it to a shop and let them properly diagnose.

-Rod

 

Do a search as there is a string about this problem. When I had it happen to my 2012 we were away, the local dealer gouged me to "update" the engine's computer. On the way home, it started flashing again, on for a while then off. Took it to my dealer, showed they quickly diagnosed a valve seat problem for which there was an extended warranty. It required the head to be replaced, they had to order the part, and it took 2 days. Annoyed about first dealer, happy with my dealer and FCA. Several thousand Kms/miles since the repair, works like a charm.