Brought this over to a Volvo dealer and they replaced the oxygen sensor in the backside of the muffler. Total cost for parts and labor was 425 dollars. Seems to have fixed the problem...

I just purchased an 2004 Volvo S60 and before I can get the vehicle home the check engine light popped up (car was sold as is). Brought the car home and hooked it up to the odb II on the laptop. Here was what it reported: P0037 H029 Heater Control Circuit Low (bank 1, Sensor 2) -- Module fuel and ai...