2008 Chevrolet Impala - Slowed to 20

After driving smoothly on the freeway i exited nd my car stopped accelerating past 20mph. My check engine light is not but today i replaced my gas pedal sensor and that didnt help. Any idea of what i need to replace next?

Nothing. Just replacing parts without finding the cause is an expensive path to failure.

You would be money ahead to have a mechanic hook a scanner to the car to find out what has actually gone wrong. Please tell them more about the problem than you told us. He also will be able to actually see the car and know what engine it has, how many miles, ect, that you didn’t tell us.