There could be many causes to this problem. A few things that could cause it would be, the fuel is not getting to the engine, meaning a problem with the fuel system (injectors, pump or filter), there is not enough electricity getting through the engine, or an o2 sensor going out.
change the plugs and wires
It will go 40mph if it's not broken 40mph is you answer by this cocky person who wrote this
often times a rough idle can occur, in addition the speedometer and cruise control will not work.
Spark plug wires? Coil pack? Dirty injector? Spark plug wires? Coil pack? Dirty injector? Spark plug wires? Coil pack? Dirty injector?
First, check all plugs and air filters.(including fuel filter by tank). Also clean your butterfly in your intake with a good cleaner and blue towels. Do this and reply back with your results.
The Dodge ram 1500 rough idle can because by a bad spark plug or spark plug wire. The rough idle can also because by a bad camshaft.
Morgan
Rough idle on a 99 Dodge Stratus is often caused by a clogged fuel filter or injectors. This prevents the engine from receiving enough fuel when needed.
I have a 2001 I had the same problem when driven through rough roads and railroad tracks, I replaced the front struts and that solved the problem. I have a 2000 that rattles too. Looking for the answer.
you need a major tuenup,plugs etc
Check for a vacuum leak
Try checking for the crankshaft sensor