Sheartbeat1616

I own a 94 Honda Passsport and it run great until a couple of months ago, I let it get low on fuel and ever since it want run right. It started to spit and sputter and had no power. So I had new spark plugs put in and an oxygen sensor, still runs the same. I noticed the coverter was getting red hot so I put it in the shop and had a new one put on. It still gets hot underneath (red hot, it bout cause on fire). It still has no power. It will run but it sluggish and you can drive it till it starts getting hot underneath. I don't want to get rid of it, cause she is my baby, and I take good care of her. Any suggestions? PLEASE HELP!!!!!!!!!!!!!!