I was driving one day and my car started to sputter and then eventually stall. It was very hard to start after this. I got towed home and looked and when i did start it, it backfired and exhaust smoke came out my intake. I already replace the plugs wires fuel filter. Dude i bought it from had the timing belt changed. I looked at it and it was really loose. So i tightened it and put it back on. It seem to be running fine in the garage, so we took it out and and started down the street and in about a half a mile it started again. There are no codes, could the tensioner be bad? or what other problem could there be? Compression is fine and their is no major engine work done to the ride. Please help