My car won't go over 20 MPH.
Hello. If the car will not go over 20 MPH then there can be a number of issues going on. If the Check Engine Light is on then the computer needs to be scanned for codes first. If there are codes in the computer then that will give me a place to start with the diagnosis. If there are not any codes then the fuel pressure should be tested and the catalytic converters checked. Either of these can fail and cause your car to run like this. It can also be a pre-cursor to a more serious internal engine issue. If you need to have this checked, consider YourMechanic, as a certified mechanic can come to your office to diagnose your acceleration issue.