when stopped at red light or when in park
because that's kind of a big engine
Check the motor mounts.
Check pLugs and wires and the vibration my be from brake pads or warped rotors
have the Fuel injectors checked out.
throttle body or idle air control value
There are many things that can cause a rough idle on this car. The computer could be going out, the engine may not have enough oil, and the engine may not be getting enough fuel or electricity.
The oxygen sensor, if defective, will give inaccurate readings to the engine management computer and may lead to a rough idle.
Idle control valve - a part that costs about $200.
The most common reason for an engine not to start is a lack of fuel. A plugged air filter can cause and engine to idle rough or not idle at all.
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.
It's extremely unlikely. Much more likely is rough running (usually due to engine management fault) causing a lack of oil pressure. Also, keep in mind that an excessively worn engine can cause both low or erratic oil pressure and rough running, but this will usually be accompanied by a knocking noise.
I blown head gasket can cause an engine miss which one cause a rough idle.