Just got my 2015 HLE back from the dealership after a complete motor rebuild. That's another story for another thread. Connecting rod bearing failed. Just driving around the house to break it in and am getting chk engine. 520209. Does anybody know what this code means? I saw a thread that mentioned Oxygen sensor heater 1 error.. I'm reluctant to take it back to the dealership as they had it for more than 2 months for the motor warranty. I checked the sensor wires and they seem OK.. It seems to be running fine.. Any help is appreciated..