I chased a misfire on cyl #2 in my 2004 R for 35,000 km, did the plugs, did the coil packs. I finally took it to a local independent Volvo shop that had the correct software to see that the misfire was only there on a COLD start up and that the #2 injector was holding open when cold and flooding the...

If you are getting misfire codes or even the dreaded random misfire code and have replaced coil packs and plugs to no avail here is what I can offer. IF the misfire shows up during a cold start up or a cold idle, you can hear it at the exhaust, sort of a puff puff, then you may have a bad injector. ...