This sensor for your 1986-88 Ford Mustang 5.0L is commonly referred to as the MAP sensor (Manifold Absolute Pressure). It is located on the firewall behind the intake manifold & provides manifold vacuum readings to the PCM. These sensors can go bad over time and need to be replaced.
Got the product a day or two before expected. Simply unplugged the vaccum line, the sensor, and loosened the two bolts holding the factory sensor. The new one goes in place of old one and hooks up in less than two minutes. Let my 88 gt ttop idle for 30 minutes and had no fluctuation in idle like with the old Map sensor attached. Quality product that looks great and solved my idle problem. Totally recommended if you have idle problems.