I just replaced my egr valve and got rid of the rough idle, but only after the engine is warmed up. Should the car idle rough when it is still cold and not up to running temp. I live in Nebraska and our mornings here have been about 30. Let me know what you think.

 

Come on now.....nobody knows if our cars are supposed to run like this when they are cold????? I know someones gotta know.

 

Cold idle should be smooth. I would check the IAC motor and clean the TB real well. If the TPS is old go ahead and change it. If that doesn't do it then go for some other sensors that may be old. MAP or O2's. The last thing to try is plugs and wires.

It's a start.

Do the steps. I put them in from easiest (cheapest) to hardest (expensive).