02 V70 XC engine cutting out

[marvin46917]

My 02 V70 XC is having a little trouble. The engine is cutting out a little. It is worse when it is in drive but not moving such as at a stop light. It does it while idling as well but not as noticable. It is supposed to use premium fuel, but there have been a few occasions where regular 87 octane was used. Could this have fouled a plug? If so, does anyone have any suggestions as far as what plugs are best to use for replacements? And what is the gap measurements? I have not changed the plugs on this car before but I don't want to take it to the shop if I don't have to.