Hey - new to the forum. My 06 XC70 threw a P0079 code. I have removed the exhaust valve solenoid cleaned it and replaced the gasket about 10K miles ago and thought it was fixed but I guess not. The last time it was just P0078.

The valve seemed to be fine - not gummed up or dirty. (SYN oil every 5K)
I was wondering if the battery could cause this as it's the original from 06.

Any thoughts before i replace the valve?

Thanks