Hello, I have a 2017 Volvo XC90. For the past month, the Check Engine Light has been on, showing code P030200 – Cylinder 2 Misfire.



I have already replaced the spark plugs and ignition coils, but the problem persists. When the engine is cold, the car vibrates and runs unevenly. However, after it warms up, it stabilizes. Fuel consumption has increased significantly—I’m only getting around 400 km per full tank now.



Compression is normal on both cold and warm engines. I also swapped the fuel injectors, but the misfire remains on cylinder 2.



The car was imported to Georgia (the Republic) from the U.S. It used to run fine on Perron 95 fuel. The issue started after I filled the tank with 98 octane fuel.



What else can I do? Should I replace or clean all four fuel injectors next? This is the only remaining potential issue I can think of. Any suggestions or advice would be greatly appreciated.

 

have you run any real time OBD data to see if you have a lean condition at some point? Most fuel trim fault codes are "averaging" so it may be you only see a lean condition in certain situations. You may also need to check the wiring harness to the coils, and you may need to do a compression and/or leak down test to make sure the valves and rings are in good working order for that cylinder. Running premium fuel would not cause a misfire but its possible you got some contamination (ie water?) in that fill up.