I just came back from a long trip and my C240 started acting up. The check engine light came on and when the car is stopped there is some slight shaking. It accelerates really slow, not like before... I was thinking it might be the spark plugs or the wires maybe?? If anyone has any ideas, please help!! My nearest dealer is about 200 miles away, so I kinda need to see if it is something simple or if I should take it to the dealer.
Has anyone here had the same problem??

Thanks in advance!
ps.
I have a confession: Prior to the trip I didn't put the premium fuel in my benz! Could this be the problem??[/align]

 

I seriously doubt it's the gas or the spark plugs. Most engines these days will run pretty good on a lower
octane gas and not do what your car is doing....ie....the shaking, etc. Sure, performance may not be at it's peak,
but it won't make the car physically shake. Unless you have really bad plugs, it's not that. I pulled the plugs
out of my '05 with over 100K miles, and they were pretty good and the car ran fine. I hate to say this, but you
could spend a ton of money here if you don't diagnose the car first. That's where I'd start in a case like this.
Then, just fix what needs to be fixed. Yes?