rough idle at stop light and in park on a 2000 chrysler cirrus 2.4 engine?

[melissa f]

ive changed the timing belt water pump an air hose engine light is on took it to advanced and they did the code thing and they said it was running to rich, so i checked all the hoses look fine the only thing thats messed up is my air filter its dirty my spark plugs look brand new even tho there 3 yrs old and i do need to change the valve cover gasket i saw it leaking when i sprayed it with cleaner but its been like that before all this vibration started it does fine when im driving oh and when im stopped my rpms go down past the 1000 the egr valve looks good its just getting aggravating ima get an air filter friday but i know thats not going to fix it please help me cus u know something so small and simple can turn into something expensive if not fixed thanks for all advice i have a haynes repair manual