If you have a volvo S80 T6 you may have a quick look at this article .The article is about to how to fix the problem that the Two cylinder misfires
Solution: use the detector to detect the fault of second cylinder misfire. Because of previous experience on the vehicle ignition coil is easy to damage, direct suspicion to the ignition coil. Demolition of the ignition coil, ignition coil ignition coil can be transposed into the three cylinder ignition. Examine the two cylinder ignition coil plug with a multimeter measuring 2,3 to open ignition switch .It shows 12.3V voltage, so there is no problems with the ignition coil power supplying system . The problems appeared in the 1 signal line. The multimeter resistance profile measurement of the line to ground resistance of 965 ohm normal should be 1962 ohms. Detection of the line to the ECU A50 foot resistance is 0 ohms. The line did not break, the problem appeared in ECU. Demolition of ECU detection corresponding to the ignition chip on the chip corresponding to two cylinder pin lead detection line, with ECU, turn the ignition switch to find the pin and the ground short circuit.
To replace the ignition chip. Loading test of two cylinder ignition is normal. When the demolition of attachment. The detecting instrument for detecting no fault codes. Car was tested normally.
Follow this way ,it can be helpful to your Volvo S80 T6 cylinder’s problem.