Hello, I have a 1999 nissan maxima se limited with 166k miles. My engine light came on a and I had it checked and its having a egr flow malfunction. No i have bought a new valve, all of my ports are cleaned out and it still sayin egr flow malfunction. After i got tha valve and cleaned tha ports i took it 2 advance and they erased tha code, and about 4 days later the light came back on saying egr flow malfunction. I really dont know what is going on. Can somebody help me please?