Year 2000 vehicle
After driving for a while (car is sufficiently warmed up) and coming to a complete or near complete stop, my vehicle will backfire out of the tailpipe for about 5 seconds (not long). It is not loud or very noticeable but if it goes on for a couple of seconds the idle will drop and the car will sputter. It does not do it all the time but here the situations where it can happen:
1. Cool-cold days
2. Cool rainy days (never noticed while warm-hot outside)
3. When complete stop or slowing while going up a hill.
More info…
About 1 year ago I got the spark plug holes wet and the car ran poorly. I ended up changing the plugs but not the wires (never in stock in my area). I tested the resistance of the ignition coils and they seemed within spec.