What's wrong with my 2003 Impala?

My 2003 Impala shifts hard! Also when I come to a stop it starts to choke and die, same thing when I am going uphill (only when I am going slow, like turning a corner to go uphill). The engine code says that it's the EGR Valve, but I've replaced it, and it still is doing the same thing. Also last week I gave my car a major tune up:



Changed spark plugs and wires

Changed air filter

Changed fuel filter

Changed Oil/Filter

Changed Trans Fluid/Filter

Changed PCV Valve

Flushed Radiator

I also added Lucas Transmission Fix, didn't help.



I've heard that you can run Seafoam through the Vacuum line. Would this help? And how do you do it?What's wrong with my 2003 Impala?done everything...how about a wash and wax? have you looked for a vacuum leak? spraying along hoses with wd40 see if idle changes



fuel pump????What's wrong with my 2003 Impala?Take it to the certified mechanic before you change everything else in the car.What's wrong with my 2003 Impala?make sure you have the correct amount of fluid in the transmission then go for a drive with the car at operating temp. if it still shifts hard look for a vacuum line that came off the trans where your shift module is. otherwise take it to a trany shop.