I have a 2003 Protege ES that I just had an OBX header put on. I did the nonfoulers trick to fix the bank 2 CEL. Now I have a P0031 CEL. I tried to clear it and tried to unplug and replug the clip for the first bank o2. It keeps coming back. I have never had it before and since the header install last Friday it doesn't want to leave. Any ideas? I don't want to replace the o2 if that may not be the problem. Thanks in advance.