Hi, I'm new to this forum. I would apprieciate some help. I just purchased a 2000 civic si with 131k. It has a d.c. header and AEM cai. the engine is the stock b16a2. After driving the car a few hundred miles the mil (engine light) came on with the code p0420. I changed the oxygen sensor and also did the spark plug defouler trick thing I read about. Now, however, after I canceled that code the mil came on again with the code p0141. It says something about the 02 sensor heater circuit. Now, the sensor I put in didn't have the oem plug, just butt connectors. You have to cut the old plug and crimp the wires (I know you guys aren't dumb). I double checked everything and I still got this code. Any thoughts, anyone? Please help