[Guest]

I have a 2002 Chevy Impala, 95xxx miles. The car has recently been poor at acceleration, running hot, and occasionally, the check engine light would come on. I took the car to an auto parts store to have the check engine code read, and it said EGR valve. So I had that changed, and I also disconnected the battery to reset the computer. It's still not working. What else could this be?

 

[Guest]

Take the vacuum line off the egr valve and see if it runs better. Check the coolant level and condition for the overheating. It may be tune up time or the intake manifold is plugged with carbon.

 

[77Impala]

Problem with EGR Valve may not be the valve but one of the other componets that help control the valve. There is the EGR Valve Regulator, and a Differential Pressure FEedback Sensor, (which mesures the pressures in the exhaust system before and after the EGR Valve), the Engine Coolant Sensor, TPS, and MAF Sensors. Most times the DPFE is the culprit.
The overheating is most likely the result of your EGR System not working effecently allowing the engine tempature to get too high.
On cars with OBD-II engine computers disconnecting the battery will not reset the code, the code gets stored in the systems memory until it is reset with a diagnostic computer. Have the auto parts house do that for you.