Dodge Repair: rough running/ idle: 2.5L 98

Question
i have a 98 dodge stratus es 2.5l. the car will start but only if i have my foot to the floor on the gas pedal and then the car only seems to cough and not really run? Any idea what can cause this?"

Answer
Hi Stephen,
That sounds like a problem with the fuel/air ratio of the mixture being off. There are several possibilities and approaches.
First check for the presence of a fault code using the ignition key: "on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the odometer window of the instrument cluster to see if the mileage reading is replaced by "done" or by a 4-digit number preceded by a P. Let me know what you find.
The other possibilities are that the exhaust gas recirculation valve is gummed up and is not closing tightly when you slow to a stop or turn off the engine, or accelerate. That valve is located near the thermostat housing which is under the coolant filler cap on the rear of the engine. The valve is mounted sideways, its body is connected to a small diameter pipe that runs from the exhaust manifold on the back cylinder bank. It has a round top with a vacuum hose connector and a flange between the top and body of the valve. Hidden behind the flange is the valve stem which has a circumferential slot into which the tip of a screwdriver can be inserted so as to move the valve back and forth against spring-action in one direction that closes the valve. If you spray some WD-40 on the stem where it enters the valve body and then move the stem back and forth you can free-up the action so that the valve closes tightly.
That will correct the rough idle hard starting.
The other possibilities are that the throat of the throttle body is dirty which also can cause a poor mixture. So you could clean the throttle butterfly plate and the throat and the side passageway which is where idle air is inhaled.
A fault code may also tell us other reasons. But try for a code and lubricate the egr valve and let me know.
Roland