Was wondering if anyone else has installed MSDS headers on their mazda and was able to keep the CEL off for the 2nd 02 sensor. I'm at the point where I just want to give up. Long story short my flex pipe on my 3 broke for the 3rd time. Instead of trying to salvage the cut and mangled OEM manifold I decided to upgrade to the MSDS header. I've tried a defouler from CNT racing so far. didnt work. tried an ebay one with a screen on it that seemed more promising it stayed off for much longer but eventually came back on. My last hope is this "02 simulator" i saw googling this issue and it basically wires in to your 02 sensor to trick the ECU into thinking it has the proper voltage.. anyone have any luck with this or have a solution?