A stop and go is a desperation play in which you are giving 3(!) free cards to your opponent in the hopes that all three will miss him and he will fold a hand that he wouldn't fold preflop. The following conditions should be present:
<ul type="square">[*]You are first to act on the flop[*]You have no preflop FE[*]You are desperate and will need to make a move soon anyway[/list]Only condition 1 applies. This is a terrible spot for a stop-and-go.
Fold or push preflop. I would advocate for pushing. I think the possibility that the CO is attempting a steal, combined with your preflop FE and your decent cards, makes this a better than 50-50 move.