Any info will be greatly appreciated! I have a 1998 Honda Accord V6. CEL came on? Car surging while idling and dies?

CEL was on a while back for close to 8 months. Changed gas cap. Light was
still on. I never had code ran..fast forward..CEL went off one day, again never
had it cleared or read. Light stayed off for approx 1 1\2 months. Never a
problem with the car, light on or off. I filled my car up (reputable busy station).
I did not use car the next day. The following day the car had a hard start (it
had also gotten real cold this week) but car sorta sputtering.Drove to work
and back. Next day started car and idle good at start (choke good?) but soon
as choke released idled lower than normal, then a surging idle, exhaust out of
tail pipes had a light misting of some darker fluid (oil??). I think I hear a slight
misfire (not sure I'm not a mechanic). CEL light came back on (it's Not
flashing). Any ideas? I'm going to get codes ran tomorrow. I just put some
heet w/injector cleaner in yesterday, but haven't driven it. Only started it and
let run. It's been sub zero weather here. It's been a great car until a week ago.