Intermittent Check Engine Light

How many O2 sensors did you replace and what brand did you use?

Take it back to the shop,and get them to check whats wrong? Like Mark mention how many o2 sensors you did replace,and sometimes aftermarket stuff just doesnt do the trick.

Thanks for responding. All I know is that it's Volvo manufactured parts. This has been going on/off for over several months. Replaced oxygen sensor twice.

Hi ho hi ho it's back to the shop you go. You paid for a service and should expect that service to work. I'm hoping that it's not the catalytic converter.