I have a 2001 GSR and I have a rough idle and throw a P505 code. I clean the throttle and the IAC valve the code went away. After 2- 3 days, I got the same code 505 again and the idel jump up and down like crazy. So I bought a new IAC valve and replace it. The same problem come back again. Now I don't know what I need to do next. Need some serious help. Thnks