In August of 2018, I bought a one owner '98 sierra with only 100k miles that was well taken care of and hadn't had any issues for a year now, until the past few weeks. It started idling rough, so I replaced the sparkplugs. It was still idling rough so I was going to replace the wires and distributor cap, but before I had the chance it wouldn't start after work one day. I had it towed to a local mechanic I thought I "knew." He replaced the serpentine belt and tension pulley and put in a new battery before he asked me any questions. Because I thought I could trust him, I had my wife pick up the car. The good news is the car now starts. The bad news is that it idles rougher than it did before. Did I get bamboozled?