Bad Mechanic Visit Left Honda Smoking and Struggling?

I had very similar symptoms with my 2018 Honda Insight Hybrid last month. Initially thought it was minor, but turned out to be a combination of a cracked exhaust manifold and a failed oxygen sensor. The black smoke and rough running were dead giveaways. My mechanic found the exhaust leak was allowing unmetered air into the system, throwing off the fuel mixture. This explained the poor fuel economy and performance issues. The repair involved replacing the cracked manifold, gaskets, and both oxygen sensors. It was a serious job that took a couple of days to complete. This isn't something you want to leave unattended, the exhaust leak can damage other components if left unchecked. Based on your symptoms, I'd recommend getting a diagnostic scan and exhaust system inspection done at a certified hybrid specialist.

Thanks so much for your detailed response! that sounds exactly like what I'm experiencing. You've given me some peace of mind knowing it's a fixable issue. Would you mind sharing how much the whole repair ended up costing you? Also curious if you've had any other issues pop up since getting it fixed? I'm a bit nervous about costs but definitely don't want to make things worse by waiting too long.

Hey! Happy to give you an update. My repair turned out to be a good investment, the Lambda sensor defect was definitely the main culprit, and getting it fixed made a world of difference. The whole thing, including the exhaust leak repair, came to 265€ total. Since getting it sorted, my Insight's been running like a dream! No more black smoke, rough running, or any of those annoying symptoms. Fuel economy's back to normal too, which is a huge relief for my wallet. It's like driving a different car now, smooth and responsive, just how it should be. Trust me, getting it fixed sooner rather than later was the right call. These issues can snowball if you leave them too long. Been about a month now since the repair and haven't had a single problem pop up. Honestly, wish I'd done it even sooner! Let me know how you get on with yours. Always good to hear how these things work out!

Thanks for all that info! Just got back from a certified mechanic today actually. You were totally right, I bit the bullet and got it checked out. Similar to your case, they found the oxygen sensor was shot and there was a small exhaust leak making everything worse. The whole repair took about 4 hours, and while the bill wasn't tiny, it was worth every penny. The car's running amazingly now, no more black smoke, the jerking's gone, and it feels like I got my old car back! Engine's purring like a kitten again. You really helped me avoid what could've been a much bigger headache. I was nervous about getting it fixed after my last mechanic messed things up, but this new place was fantastic. They even showed me the old parts and explained everything. Really appreciate you sharing your experience, it gave me the push I needed to get this sorted properly. Time to enjoy my smooth-running car again!