C340 Captain diverting to a suitable airport due to a rough running engine.

Narrative

Aircraft left engine began running rough. Engine monitor showed #2 cylinder high EGT; low temperature. Oil pressure was normal. I had my daughter on board and decided it was best to land at the closest suitable airport which was ZZZ. I requested priority handling and landed without issue at ZZZ. After landing I tried several things to diagnose problem including running the high pressure boost pump. That appeared to work on a subsequent run up. Because it was dark and I did not want to take unnecessary chances I called it a night and went to a hotel. That evening I reviewed the issue with a mechanic and we both agreed it sounded like a clogged fuel line. The next morning I checked the exhaust for any oil residue and there was none. I reviewed the preventative maintenance list with my mechanic and opted to check the spark plugs and fuel line on that cylinder. Everything appeared normal and I departed the following day after a full runup.There have been no further issues with the cylinder in question.