The power steering belt on the n15 Nissan Pulsar is located between the passenger cab and the engine. This is a difficult area to work on at home. It may be best to see a professional as exposure of the area is difficult to achieve.
If the check engine light stays on for the Nissan Pulsar n16, you would need to check the engine in order to clear codes. You can take the car for service and the problem will be diagnosed and restored to normalcy.
The 1983-89 Nissan Pulsar with the 1.5 1.6 & 1.8 engine have a cam belt. The belt must be replaced at 60,000 miles. Warning: All of these engines are Interference engines. If the belt breaks, serious engine damage will occur.