BMW 3-Series O2 Sensor Issues: Help & Solutions Needed

Thanks for sharing your experience! My Beemer's got about 146595 KM on the clock, and I've recently had it serviced. I've got the same symptoms you mentioned, excessive fuel consumption and that annoying check engine light. Got the error codes checked at a local shop and they pointed to the O2 sensor circuit. Good to know your fix was relatively straightforward and affordable. My engine's actually running a bit rough too, especially when cold. Sounds like I should get those wiring connections checked first before replacing the whole sensor. Did you notice any improvement in engine smoothness after your repair?

Thanks so much for all that detailed info! It's super helpful to know about the adaptation period, I'll definitely keep that in mind and not panic if it takes a few days to smooth out completely. Really appreciate the tip about getting them to check all the connections too. Makes total sense to fix everything while they're already working on it. I've actually just booked it in at my regular workshop for tomorrow morning. They're going to do a full diagnostic on the wiring harness and check for corrosion, just like you suggested. The symptoms match up so perfectly with what you experienced, I'm feeling pretty optimistic that this might be the solution I've been looking for. I'll definitely keep you posted on how it turns out. Really grateful for you taking the time to share your experience, it's exactly why I love asking fellow BMW owners for advice. Fingers crossed I'll be back soon with good news about a smooth-running engine and normal fuel consumption!