I once bought "cheap autozone wires" for an old cavalier I used to have, and shortly after it would sputter and lose power at completely random times. It started up and idled fine though. Anyways, it turns out there was a tiny pin-hole in one of the wires which was probably causing an electrical light show under my hood as I drove. Anyways, after I changed them for some new ones, the problem disappeared.

That car had over 230,000 when my parents sold it to some kid to use as a derby car. I still say they shoulda kept it. Only reason it ever had problems was because I started driving it, lol. My mom drove/drives like she was/is a grandma.