Car drove fine all day in the morning and at night. Parked my car to go in the office and came out to start the car. It started pouring like crazy! A minute later my CEL came on, traction control light turned on and my cruise was flashing. Plugged in my ap and pulled the code p0138. Forgot to mention I have a 2011 wrx. From what I've read, it a bad rear 02 sensor. Anybody have any experience with this? I would take it back to the dealership but my car has a cbe, intake, and a stage 1 map. Don't know if it'll be under "warranty". Anybody with any solutions or have experienced this before?