When you begin to notice that your previously velvet-smooth ride is becoming a little bit choppy, look at your Cadillac spark plug wires. They are often the cause of engine misfiring, which will make your ride a bumpy, halting affair. In the past, misfirings were immediately observable - there's nothing like signature sound of gunfire and blowing smoke that you saw in older models. Nowadays, because of modern engines that can regulate or moderate misfirings, sometimes it is harder to detect until the engine is misfiring almost constantly. Since it is hard to hear misfires anymore, new emissions-control standards require the engine computer's on-board diagnostics (OBD) to log trouble codes for each of the cylinders, which can make it easier to trace the problem. Often, the issue can be traced to loose terminals. That can happen when the plug wires are mishandled during other kinds of car maintenance operations. A mechanic or DIYer can accidentally tug on the wires, disconnecting or loosening them at their boots. So when you need to disconnect your Cadillac spark plug wires, be careful! Do not pull on the wires, but grasp the plug wire and gently remove it. Do not do this when your engine is cold, since the connectors will become looser in hot conditions. Remember that plug wires are weakest at their boots, so be gentle and use a left and right twist before removing might help. There are also special tools just for this purpose, so it can be worth the investment to buy them when replacing your Cadillac spark plug wires.