Problems with Leon Seat 2016: black smoke, drop in performance and exhaust leaks

Hey, I had a similar problem with my 2014 Leon Seat, which is a little older than yours. But I'm not a mechanic either. It's close, but in my case it was a defect in one of the lambda sensors, which also led to reduced engine power and that damn Check Engine light. I went to my garage and they fixed it. It cost me around €375. Because of your exhaust, which smells bad and leaks, there could be something else going on. Perhaps a bit more information about your car? Maybe then I can help more precisely. Hang in there!

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Hey, thanks for your help! My Leon has about 80236 km on it and I haven't really had many problems apart from the typical wear parts. That's interesting about the lambda sensor, that could also be the case for me. I'm also unsure about the exhaust, I'd probably have to see my buddy, he often tinkers with cars. What exactly would you like to know? I'm grateful for any tips!

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Hey, I had exactly the same problem with my 2015 Leon. This constant bitching from the car, especially that stupid smoke, almost drove me crazy. Your suspicion about the exhaust aftertreatment malfunction could be correct. That was exactly the case for me. It turned out that the exhaust gas recirculation valve (EGR) was broken. This means that the engine is not burning properly - hence the black smoke and the severe loss of power. The Check Engine light indicates exactly that. I then drove to my regular workshop. They did a diagnostic test and found the fault straight away. They then replaced the EGR valve and checked the entire exhaust system - because you also mentioned an exhaust leak and a strong smell, this was probably the case for you too. After replacing it, everything ran smoothly again, no more smoke, no loss of power and the smell was gone too. So yes, I would recommend that you go to the garage and have it checked. In my case, the repair cost around €600, but this can of course vary slightly from garage to garage. Good luck and hopefully your car will be back in shape soon!

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Hello, thanks for the helpful answer! The EGR valve in particular is a great tip, I hadn't thought of anything like that. If that is the case, then it would also explain why my Seat is acting up. As far as the exhaust is concerned, I will definitely visit my garage, I don't have the confidence to do it myself. Maybe it really is just the EGR valve and the exhaust leak is perhaps just a minor issue... I certainly hope so. Thank you very much for your help and I wish you a happy new year! I'll keep you posted on what the garage says.

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Hello, Have you ever had the engine read out? Personally, it sounds to me as if the lambda sensor (before the catalytic converter) could be defective. This should definitely be checked.

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