Ok so my protege threw a cel for a p0401 meaning insufficant flow in egr 2. This meaning egr valve needs cleaned or replaced correct?

 

I just went through this with a 2002 protege, took off the egr valve, cleaned it, put it back on, sprayed "seafoam" inside of the throttle body ( a lot of it to let it soak carbon loose), let it sit for about 20 minutes. Started the car, drove it for 2 days, the light went off, hasn't been on for a few weeks.