Annoying Problem

Before I call the shop that tuned my car I figured I'd post here first. Lately my car's been hesitating and popping (slight backfires in header) in low rpms, 2000-3000. As soon as I get past 3000, everythings fine...doesn't seem to be any lose of power. Thinkin I might be running a little rich, but just looking for opinions before I go and mess with things. Any chance O2 sensors could cause anything like this? I plan to change them anyway since they are probably the originals, just wondering though.

Thanks
Dave

I know the #3 plug wire was against the header a while back and melted the casing a little but didn't do any real damage. And that happened monthes ago, before I even had it tuned. I just checked it and rewrapped it with electrical tape.

But what was wrong with your plug wires?