It is not a good idea to drive a vehicle with a clogged EGR valve. While you can technically drive your vehicle with a clogged EGR valve, you should not continue to drive it for extended periods of time. A clogged valve can cause your engine to stall, and it can also cause harmful emissions from your tailpipe. In addition, you might be burning more fuel than necessary due to decreased fuel economy. If you have a clogged EGR valve, you should either clean or replace it as soon as possible.