Renault Spider oxygen sensor heater fault

That sounds super frustrating! I've got a Renault Spider too, and I had something similar happen a while back. For me, it turned out to be exactly what you're thinking – a corroded connector. Have you had a look at all the connections near the exhaust system? How did you test the sensor itself?

Cheers for the tip! I had a quick squiz at the connectors and they seemed ok at first glance, but maybe I need to give them a proper once-over. How exactly did you test the sensor and find the dodgy connection? Any special tools needed, or is it just a visual check?

Given your symptoms and the fact you suspect the wiring, and considering my personal experience, it definitely sounds like a cable or connector issue. The best course of action is to take it to a trusted workshop to have all car components thoroughly inspected. It is the safest and most efficient way to diagnose and address the oxygen sensor heater failure. A visit to the workshop should set you back approximately 95€.

Thanks a bunch for the advice! I took it to the mechanic, and you were spot on – it was a corroded connector, just like you said! All sorted now. Really appreciate the help!