Seeking Advice on Black Smoke, Power Loss, and Suspected Exhaust Leak in 2012 Lexus LFA

Hey there! I had a pretty similar hunch with my 2010 Lexus IS F a couple of years back. Reckon I have some experience with cars, not a pro or anything, but I ain't naive either, just so you know where I'm coming from. Took mine to the local garage, same symptoms like yours - black smoke, drop in power, and stinky fumes. They ran a couple of tests and it turned out one of my lambda sensors was on the fritz. These buggers regulate the fuel-air mixture, so a faulty one can cause all kinds of annoying symptoms, like the ones you're experiencing. I ended up paying around €375.00 to get it squared away, not cheap, but it sorted the problem. Worth checking if it's the same for your LFA. Is your car a manual or automatic? And have you noticed these issues during all types of driving or just specific situations, like on the motorway or city driving? Knowing this info might help to pin down what's going on. Hope this helps a bit, keep us posted!

Hey, appreciate the tip! Honestly, didn't think about the lambda sensors at all. My LFA is an automatic. Interestingly, I've been noticing these issues mostly during city driving, now that you mention it. Less noticeable on the motorway. Mileage is at 188986KM and the service was couple of months ago. They didn't pick up any sensor issues then, but given how disruptive this has been, I'll get them to run their diagnostics again and specifically check the lambda sensors. Thanks again for your help! Will update here as soon as I figure it out. Cheers!

Hey, no problem at all! Always glad to share my experience and help another motorhead out. Now, based on what you're saying about city driving, sounds like the exhaust leaks might be a bigger issue. When you're idling or moving slowly, the leak can actually cause the sensor to read false lean conditions, forcing the ECU to pump in more fuel, hence the black smoke. At highway speeds, the increased exhaust velocity can actually help minimize the effect of the leak, which could explain why the problem's less noticeable on the motorway. Since you had a service done recently, I would definitely check back with the garage to ensure they performed all necessary tests on the last visit. In addition, have them recheck the lambda sensors, but also consider having the car thoroughly inspected for any exhaust leaks. You might need a new gasket or in severe cases a new pipe. Lookin' forward to hearing what you find out. Good luck with it! And remember, it's all about having fun, even with the problems. Cheers!

Thank you so much for taking the time to help me out! I honestly wouldn't have given the exhaust leak so much weightage. But you've given me some new insight that makes a lot of sense. I'll be sure to bring up these points with my garage - the lambda sensors, possible exhaust leaks and gasket condition. And I agree, these unexpected issues are part and parcel of the car ownership experience. Can't deny there's a bit of a thrill in troubleshooting and getting to the bottom of this riddle. I'll certainly keep you updated. Cheers and thanks again! You're a legend!