I have a CEL problem on my 355. I comes on for a while (maybe 5 minutes) and then turns off. I pulled the codes and got: 1212 4131 1211 I know that a 4131 is "Compressor connection signal". I have searched and haven't seen a good explaination on what this is and what should be done to fix it. What should I do? I changed the O2 sensor after getting a 1212 code. Then I changed the cam phase sensor after getting codes of 4114, 1212 and 1211. This is all in the last 3 months I have cleaned the connector on the ECU. Thanks for your help, Enzo