Later got code that 2nd cylinder misfires. Driving became uncomfortable. Changed O2 sensor (front one, put new Bosch sensor). Misfire continued and turned later into multiple cylinders misfire. Changed 5 spark plugs. Multiple misfire continued. Driving with multiple misfire was almost impossible. Changed coils on 4 and 5 cylinders (put used ones from another volvo) and installed original coil from 5th cylinder to 2nd cylinder. Misfire ended. Drives smoothly. But still "Check Engine" and p0130 02 code. Unplugged battery and left key in ON position over the night in attempt to delete it from computer's memory but code is still there. Any suggestions how to delete this ""Check Engine" and p0130 o2 would be highly appreciated. Thank you in advance.