Any vehicle with a gas engine that does not have a oxygen sensor. Usually before 1985. All but the last years of carburation equipped cars were "open loop"
The system without feedback is known as open loop system. The examples of the open loop system are bread toaster, oven ,washing machine. The open loop systems are inaccurate & less complex.
Imagine a room with a central heating radiator fitted with a control valve. Open loop control describes how the markings on the valve are used to control room temperature. For example, experience may...