How to troubleshoot a faulty oxygen sensor in a Vauxhall Astra?

Recently, I've been experiencing erratic engine performance and reduced fuel efficiency in my Vauxhall Astra. I suspect that the oxygen sensor might be malfunctioning. What steps can I take to diagnose and fix this issue?

First, you'll need to locate the oxygen sensor in your Vauxhall Astra. It's typically located on the exhaust manifold or close to the catalytic converter.

Using a multimeter, you can test the sensor's voltage output. If it falls within the acceptable range, then the sensor is most likely functioning properly.

If the voltage is too high or too low, you'll need to replace the oxygen sensor. Make sure to get an OEM sensor for the best performance.