I've got a 2001 2.4/auto Stratus sedan. It's got 134k miles on it. Plugs are a little more than a year old.

The mileage has been dropping since about last summer. Highway mileage has dropped from around 31-23 and the around town miles went from 25-21. The idle is not smooth anymore like it used to be but not like it's missing. The other day it was low on fuel but not empty and I could barely keep it idling at all. It kept wanting to die if I didn't keep a little throttle on with my foot. After filling it, it idled a little better but then it did sound like it was missing. I drove home and the idle went back to how it's been as of late. It seems to run quite well other that the vibrating idle and lack of fuel efficiency. No hesitation and with plenty of power and acceleration.

Thanks.

 

Pulled off the throttle body and cleaned it. Replaced the year old Autolite platinums with the regular ol' Champions listed on the label under the hood, new plug wires and an air filter. Drove it 312 miles round trip to Sacramento and back this afternoon. 30.16 mpg. I'm happy again.