Car runs great but on a cold start it has a rough idle like a bad plug or fuel filter replaced both after car is warn will start fine every time

I'd be pulling the spark plugs and checking for condition, gap, fouling, etc.

Throttle plate may need cleaned and check your plugs.

Spark Plugs

Air Filter

Fuel Filter

I actually had to replace my EGR valve and the gasket. I clean the valve well and reused both. I don't think the gasket sealed well enough though. So I went ahead and got a new valve, gasket and changed them. It runs a lot smoother now.

Hi, Try to replace fuel filter. It maybe clogged up and making engine run rough or poor. Also check and replace spark plugs. A bad spark plug will make it run rough too. Good luck.

does it run rough after warm up??or cold too,,u mite have a vacuum leak,,,take some injection cleaner spay,,carb or brake cleaner spray,,seen many different spays used,,,but spay around air intake,,around base,,see if engine will stumble,,also seen temp censer problems,,where its tell the ecu that the motors cold,so it rich-ens the fuel,,injector,,hoped it helped,,

The wire harness to the fuel pump sending unit may be going bad which is common to happen. The harness is around $15.00 and it runs from the frame to the top of the gas tank. The other thing to is the fuel pump sending unit may be going bad and the float in side that measures the amount of gas, has gone bad and the unit may need to be replaced. As for the rough idle, it cold be related to the fuel pump starting to go bad and the fuel pressure is just marginal to keeping the engine running. The fuel pressure during cold start should be 62-65 PSI and should drop about 5 PSI when the engine is running. The other thing to that would casue a rough idle, would be time for a tune up, "spark plugs, wires and distributor cap and rotor, fuel filter"

Bad EGR valve comes to mind here. Assuming the plugs are good, the EGR valve woiuld be what I'd look at.

To update my earlier repair on the 2001 6 cyl Escape: When cold, and when the ignition was turned over but no accelerator pressure given, the rough idle finally returned the P0303 code again when the check engine light came on indicating that it wasn't caused by the plugs or the coil. FYI, I had replaced the intake manifold gaskets during the original repair and just prior to that I had replaced the fuel filter which was very dirty (I cut it open to see).

The repair manual referred to fuel injectors as a possible problem. I have run three tanks of fuel using different injector cleaning products and am very pleased with the results. Cold starts are much smoother and I am unable to coax out the P0303 code or any other code.

My opinion, change the fuel filter, use a fuel injector cleaner for a couple of tanks, change the plugs if the problem still exists. The coils were not the problem on my vehicle.