2003 Jeep Grand Cherokee Runs Rough

Throttle Position Sensor? Has that been replaced? Relatively inexpensive and easy to do yourself..

Cleaned the Air Mass Flow Sensor?

Cleaned Throttle Body?

Have the spark plugs and wires been checked?

When my Grand Cherokee was having similar rough idling problems, I replaced all the plugs and replaced all the ignition and spark plug wires. I also put in half bottle of fuel injector cleaner in gas tank (full, as recommended). I had both immediate improvement in power, smoother idling and my gas mileage went up 2mpg (approx).

I have a 99 jeep myself and it was my throttle position sensor.

check the O2 sensors in the exhaust manifold with a automotive meter not a code reader ,then trade it in for a diesel manual version as these are impressive but 4.7 litre gas guzler at our petrol prices about 10 dollars a gallon in the -uk and around 7/8 dollars here in spain this vehicle you couldnt give away here

have you checked the IAC, idle air control,or cleaned the throttle body and plate.

Review this reference documents: ZJ-Secc-8P-Power-Door-Locks (Page 4)

Good luck... and rated my help!!!

If you haven't changed the plugs or had the fuel system cleaned, now would be a good time to do it. The number 1 culprit for rough idles is dirty injectors or plugs. You can try an injector cleaner in a can (or bottle) for under $10 and see if it helps, and then work from there. If there isn't any improvement then if you are able to, check the plugs for any gunky buildup and if you find a bad plug, make sure you replace them all (or have them replaced) at the same time.

You do have a filter and it's mounted right on top of the pump on outside of tank...it is also the pressure regulator. You really should put a pressure gauge on the fuel system and check it out though. you may find there is a problem elsewhere. Good and proper testing is the only way to get answers about problems especially now that systems are all electronically controlled.

Check, clean EGR valve & see if that helps.

check your transmission fluid,the motor will stall when fluid is low